NOTES  ON  ARTILLERY: 


ROBINS,  HUTTON,  CHESNEY,  MORDECAI,  DAHLGREEN, 
II         '  JACOB,  GREENER,  GIBBON  AND  BENTON. 


BT 

W.  LEROY  BROUN,  M.  A., 

Lieutenant  Artillery,  Virginia  Volunteers. 


mOHMOND: 
PUBLISHED  BY  WEST  &  JOHNSTON,  145  MAIN  STREET. 

1862. 


%^> 


NOTES  ON  ARTILLERY. 


» 


NOTES  ON  ARTILLERY: 


FROM 


ROBINS,  BUTTON,  CHESNEY,  MORDECAI,  DAHLGREEN, 
JACOB,  GREENER,  GIBBON  AND  BENTON. 


BY 


W.   LEROY  BROUN,   M.A., 

Lieutonant  Artillerj  Virginia  Voluateers. 


RICHMOND: 

PUBLISHED  BY  WEST  &  JOHNSTON,  145  MAIN  STREET 

1862. 


•l! 


Entered  according  to  act  of  Congress,  in  the  year  1862, 
^  By  west  &  JOHNSTON, 

In  the  Clerk's  Office  of  the  District  Court  of  the  Confederate  States  for  the 
Eastern  District  of  Virginia. 


CHAS.  H.  WYNNE,  PEINTBB, 


PREFACE 


The  writer,  having  had  access  to  several  interesting  works  on  the 
subject  of  artillery  that  are  now  very  difficult  to  obtain,  has  con- 
cluded to  publish  these  ^' Notes,"  hurriedly  written,  as  they  have 
been,  in  a  few  spare  days.  He  does  so  with  the  hope  that  they  may 
interest  and  instruct  his  fellow-comrades  in  arms,  especially  those 
who  have  lately  enteced  this  arm  of  the  service,  and  may  in  some 
remote  degree  aid  the  great  cause  so  dear  to  his  heart. 

He  has  had  access  to  and  used  the  information  derived  from  the 
following  works : 

Artillerist's  Manual^  by  Lieut.  Gibbon,  U.  S.  A. 
Ordnance  and  Gunnery,  by  Capt.  J.  G.  Benton,  U.  S.  M.  A. 
Shells  and  Shell  Guns,  by  Com.  J.  A.  Dahlgreen,  U.  S.  N. 
Rifles  and  Rifle  Practice,  by  C.  M.  Wilcox,  U.  S.  A. 
Notes  on  Sea  Coast  Defence,  by  Maj.  J.  G.  Barnard,  U.  S.  A. 
The  Science  of  Gunnery,  by  William  Greener,  of  .London. 
Observation^  on  Fire  Arms,  by  Col.  Chesney,  Royal  Artillery. 
Military  Commission  to  Europe,  by  Maj.  Mordecai,  U.  S.  A. 
Treatise  on  Fire  Arms,  by  Lieut.  Simons,  Bengal  Artillery. 
Rifle  Practice,  by  Col.  Jacob,  Bombay  Artillery. 

He  has  also  made  use  bf  information  derived  from  the  writings  of 
Kobins  and  Hutton. 


4Ji52?3 


CONTENTS 


I. 

PAOB 

Ancient  and  Moderd  Arms *. 9 

11. 

Gunpowder.... » ; 18 

III. 

The  Smooth  Bore  and  the  Howitzer — the  Cause  of  their  Deviations..,       18 

IV. 
The  Rifle  Cannon— "Drift"  of  the  Ball  and  its  Cause 28 

V. 

Resistance  of  the  Air 40 

VI. 

Pnzes 46 

VII. 
Sighting  Guns — How  to  Make  Sights 48 

VIII. 

Classes  of  Projectiles — Classification  ,of  Fires — When  each  should  be 
used .•. 54 

IX. 

Miscellaneous   Memoranda — Care  of  Horsed  —  To   guard   against  the 
enemy's  fire — Penetration  of  Shot— Iron  Clad  Vessels 68 

X. 

Tables  of  Ranges  and  Elevations 62 


4pc:p^^o 


NOTES  ON  ARTILLERY 


ANCIENT  AND  MODERN  ARMS.  • 

The  common  sling,  no  doubt,  constituted  the  first  kind  of 
Artillery,  which  was  followed  by  the  bow  and  arrow,  and  this 
latter  weapon  was  improved  in  succeeding  ages  by  the  bal- 
lista  and  catapulta,  &c.  The  ballista  of  the  ancients  hurled 
stones  from  2  to  300  pounds  weight,  or  even,  it  is  said,  500 
pounds,  about  100  yards,  and  the  catapulta  projected  arrows 
and  iron  bolts  twice  that  distance.  These  machines  were 
in  use  more  than  a  thousand  years  before  the  Christian  era, 
when  Uzziah  had  engines  in  Jerusalem  ^*  invented  by  cunning 
men,  to  be  upon  the  towers  and  upon  the  bulwarks,  to  shoot 
arrows  and  great  stones  withal."     (2  Chron.  xxvi.  15.) 

Gunpowder  became  generally  known  in  Europe  in  1320  j 
and  about  this  time  it  was  first  used  in  Europe  to  projeot 
founded  stones  from  short  conical  guns,  made  in  the  shape  of 
an  apothecary's  mortar.  These  were  succeeded  by  FerriereSy 
made  longer  and  cylindrical  of  bars  of  iron  bound  together 
by  hoops,  with  a  chamber  for  the  powder.     The  introduction 


10  NOTES   ON   ARTILLERY. 

of  the  cast  iron,  instea^  of  the  stone  projectiles,  caused  the 

rejection  of  the  Perrieres  for  the  Culverijis,  a  gun  somewhat 

like  that  used  at  present,  of   cast  metal,  only  much  longer 

bore,  and  generally  ornamented  in  the  exterior  with  various 

devices.     There  is  one  now  at  Dover,  England,  25  feet  long, 

which  throws  a  projectile  of  18  pounds,  called  "  Queen  Anne's 

Pocket  Piece." 

« 

While  it  is  generally  admitted  that  the  use  of  artillery  be- 
came common  in  Europe  in  the  fourteenth  century,  we  should 
not  fail  to  mention,  that  the  Chinese  claim  to  have  been 
familiar  with  gunpowder  and  fire  arms  long  before  the  Christian 
era,  and  it  is  said  that  the  Moors  used  artillery  against  Sara- 
gossa  in  1118,  and  that  a  Culverin  of  4  pounds  calibre  was 
made  bj*  them  in  1132.  In  a  catalogue  prepared  in  1381,  of 
ordnance  at  Bologna,  there  is  mention  made  of  a  copper  gun 
which  carried  a  ball  of  361  pounds'  weight,  and  of  three  iron 
ones  which  carried  square*  projectiles.  In  the  repository  at 
Woolwich,  there  is  a  gun  marked,  *'  Henry  VI.  1426,"  with  a 
movable  breech  ;  thus  showing  that  breech-loading  cannon  are 
of  the  very  earliest  construction.  Divers  calibres  were  early 
made.  Charles  VIII.  of  France  restricted  his  artillery  to  six 
different  calibres;  and,  when  invading  Italy  (1494),  carried  in 
his  train  1,000  hacquebuttes,  or  hand  guns,  weighing  about 
50  pounds  each.  These  were  fixed  with  a  rest  or  stand. 
Shortly  afterwards,  a  lighter  gun  was  made,  called  an  arque- 
huse.  In  1521,  the  Spaniards  gained  a  victory  over  the 
French  by  the  employment  of  2,000  arquebusiers  and  800 
musketeers,  "  who  now  appeared  for  the  first  time  discharging 
bullets  of  two  ounces  weight."  We  thus  see  that  cannon  had* 
been  in  use  two  hundred  years  before  the  introduction  of  the 
musket.  • 

All  the  various  systems  of  calibres  that  were  first  intro- 


ANCIENT  AND  MODERN  ARMS.  11 

duced  in  Europe  were  finally  reduced  to  the  French  or  Ger- 
man system,  or  to  a  combination  of  them.     The  French  sys- 
tem consisted  of  calibres  of  32,  '16,  8  and  4  pounds.     The* 
German  consisted  of  48,  24,  12,  6,  3  and  IJ  pounds. 

A  system  of  uniformity  in  the  construction  of  guns  was 
only  introduced  in  France,  in  1732,  by  Valiere,  who  caused  a 
prescribed  standard  to  be  adopted.  But,  in  1765,  Gribeauval 
effected  the  most  important  changes  in  artillery.  He  dimin- 
ished the  charge  of  powder  from  one-half  to  one-third  the 
weight  of  the  ball,  and  thereby  made  the  gun  much  lighter ; 
he  disposed  the  horses  in  double  file,  having  been  previously 
arranged  in  single ;  he  introduced  iron  axle-tree^  cartridge 
instead  of  loose  powder,  elevating  screws  and  tangent  scales, 
•and  compelled  all  the  arsenals  to  make  the  work  according  to 
fixed  dimensions.  Afterwards,  he  reduced  all  field  carriages 
to  two,  making  the  wheels  of  the  limber  and  of  the  carriage 
the  same. 

In  1850,  the  Emperor  Louis  Napoleon  proposed  and  caused 
to  be  adopted  in  the  French  service  only  one  calibre  for  field 
service  a  12  pounder  howitzer-gun,  to  be  used  with  solid 
shot,  to  supply  the  place  of  the  8  and  12  pounder  guns  and 
of  the  24  and  32  pounder  howitzers.  All  the  field  batteries 
in  the  French  service  in  the  Crimean  war  consisted  of  these 
Napoleon  guns,  as  they  were  called,  each  drawn  by  eight 
horses.  In  1856,  it  was  proposed  to  retain  in  service  in  the 
old  United  States  only  one  calibre  for  field  service,  very  simi- 
lar to  the  new  Napoleonic  gun.  The  piece  was  to  be  brass,  of 
12  pounder  calibre,  16  calibres  long,  weight  1,200  pounds  ; 
charge  of  powder  2i  pounds,  stme  as  in  the  old  iron  12 
pounder.  The  weight  of  this  gun  and  carriage  would  be  only 
600  pounds  more  than  the  6  pounder  field  piece  with  its  car- 
riage.    To  give  great  mobility  to  a  portion  of  the  battery,  it 


J2  NOTES  ON  ARTILLERY. 

was  proposed  to  retain  in  the  service  the  light  12  pounder 
howitzer. 

.  We  thus  see  how  gradual  the  improvements  in  artillery  have 
been.  It  was  many  years  before  field  artillery  was  separated 
from  siege  and  garrison ;  and,  even  in  1830,  a  gun  of  24 
pounder  calibre  was  the  heaviest  mounted  on  the  sea-coast 
batteries  of  the  United  States,  where  now  we  find  10  inch 
columbiads,  casting  a  ball  of  130  pounds  weight,  with  a  charge 
of  16  pounds  powder. 


GUNPOWDER.  IS 


♦  II. 

GUNPOWDER. 

The  Chinese  claim  to  have  been  familiar  with  gunpowder 
long  anterior  to  the  Christian  era.  We  know  not  how  much 
credit  to  give  to  their  historic  records,  as  they  also  claim  to 
have  recorded  astronomical  observations  of  phenomena  that 
occurred  thousands  of  years  prior  to  the  period  assigned  for 
the  creation  of  the  earth  in  the  Mosaic  cosmogony.  By  some 
it  is  supposed  that  the  use  of  gunpowder  was  introduced  into 
Europe  by  the  Saracens.  Roger  Bacon,  in  his  Treatise  de 
Nullitate  Magise,  Oxford,  12 J 6,  gives  the  component  parts  of 
gunpowder;  but  it  only  became  generally  known  through- 
out Europe  in  1320,  through  the  exertions  of  Bartholdus 
Schwartz. 

Gunpowder  is  composed  of  nitrate  of  potassa,  charcoal  and 
sulphur,  combined  in  proportions  slightly  varying  in  different 
countries,  intimately  mixed  and  granulated.  The  following 
table  gives  the  proportions  required  by  the  atomic  theory  and 
those  used  by  different  nations  : 


14 


NOTES   ON  ARTILLERY. 


TABLE  OF  COMPOSITION  OF  DIFFERENT  GUNPOWDERS. 


•    ■ 

Nitre. 

Charcoal. 

Sulphur. 

Atomic  theory  would  require 

74.64 

1357 

11.85 

United  States  Military,    . 

76 

14 

10    • 

United  States  blasting  and  mining, 

62 

18 

•20 

English,            .         .         . 

75 

.15 

10 

French  national. 

75 

12.5 

12.5 

French  sporting, 

78     ,. 

12 

10 

Prussia, 

75 

13.5 

11.5 

Russia,    . 

73.78 

13.59 

12.63 

Austria, 

72      • 

17 

16 

Spain,      . 

76.47 

10.87 

12.75 

Sweden, 

76 

15 

9 

Chinese, 

75 

14.4 

9.9 

The  explosive  power  of  gunpowder  is  due  to  the  rapid  con- 
version of  the  solid  constituents  into  Jieated  gases.  Carbonic 
oxide,  carbonic  acid,  sulphurous  acid  and  nitrogen  are  iinme- 
diatelj  set  free,  leaving  a  residuum  of  sulphuret  of  potassium. 
It  is  calculated  that,  without  a  change  of  temperature,  the 
gases  developed  would  occupy  a  space  nearly  one  thousand 
times  greater  than  powder  in, the  solid  form.  But  at  the  in- 
stant of  change  from  soli-d  to  a  gaseous  condition,  we  know 
great  heat  is  developed  thereby,  causing  the  gases  to  occupy  a 
much  larger  volume,  and  increasing  vastly  the  explosive  power 
of  fixed  gunpowder.  This  "explosive  power"  is  diiferently 
estimated  by  different  experimenters,  depending  on  the  heat 
which  they  assume  to  be  generated  at  the  time  of  explosion. 

Robins,  who  neglected  entirely  to  consider  the  heat  gene- 
rated, estimated  the  explosive  force  of  gunpowder  at  1,000 
atmospheres ;  Hutton  estimated  the  force  at  2,050  atmos- 
pheres; Dr.  Gregory  at  2,250  j   Gay  Lussac  at  2,137;   and 


GUNPOWDER.  15 

Piobert  estimated  the  force  at  as  much  as  7,500  atmospheres. 
The  great  difference  due  to  these  estimates  is  due  to  the  fact, 
that  it  is  impossible  to  estimate  accurately  the  amount  of  heat 
generated  at  the  instant. of  explosion.  * 

The  solid  matter  of  powder  is  not  instantaneously/  converted 
into  gases.  It  requires  an  interval  of  time,  no  matter  how 
short,  to  produce  entire  combustion,  and  the  time  required  for 
the  same  weight  of  powder  depends  on  the  size  of  the  grain. 
The  larger  the  grain,  the  longer  is  the  time  occupied  in  com- 
bustion. Hence,  in  rifles  and  sporting  guns  very  fine  grain 
powder  is  used ;  while  for  guns  of  heavy  calibre  large  grain 
powder  is  required.  Were  the  powder  in  a  12  pounder  gun 
instantaneously/  converted  into  gas,  it  would  necessarily  burst 
the  gun.  Time  is  required  to  overcome  the  inertia  of  rest  of 
the  ball.  And  as  inertia  is  proportioned  to  the  mass,  the  tirpe 
reqaired  for  the  combustion  of  powder  to  safely  project  a  ball 
from  any  gun  is  proportioned  to  the  weight  of  the  ball;  hence, 
the  larger  the  ball,  the  larger  the  grain  of  powder  that  is 
used.  *  . 

It  is  said,  that  fn  the  large  Federal  gun  which  projects  a 
.ball  of  400  pounds,  the  grains  of  the  powder  used  are  larger 
than  chestnuts. 

The  conversion  of  a  portion  of  the  charge  produces  suflii- 
cient  force  to  impart  motion  to  the  ball,  and  its  velocity  con- 
tinues to  increase  until  all  of  the  charge  has  been  converted 
into  a  propellant  gas.  By  increasing  the  length  of  the  bore 
too  much,  friction  of  the  ball  against  the  bore  is  Increased, 
and  its  initial  velocity  thereby  diminished.  By  increasing  the 
charge  of  powder,  a  portion  of  it  is  expelled  from  the  ^un 
before  it  is  converted  into  gas,  and  thereby  the  velocity  of 
the  ball  diminished  by  adding  the  weight  of  the  unconsumed 
powder  to  the  weight  of  the  ball  to  the  projectile. 


16  .  NOTES   ON   ARTILLERY. 

From  many  careful  experiments,  Dr.  Hutton  by  induction 
inferred  the  following  laws : 

1.  The  velocity  varies  as  the  square  root  of  the  charge. 

2.  The  velocity  of  the  projectile  increases  to  a  certain  in- 
crease of  charge  ;  beyond  that,  it  diminishes. 

3.  The  velocity  of  the  ball  increases  in  a  somewhat  less 
ratio  than  the  square  roots  of  the  lengths  of  the  bore,  ^and 
somewhat  greater  than  the  cube  roots. 

4.  The  range  increases  nearly  as  the  square  root  of  the 
velocity ;  hence,  the  range  is  nearly  as  the  fifth  root  of  the 
length. 

Hence  we  see,  by  increasing  the  length,  a  very  slight  in- 
crease of  range  is  obtained. 

For  field  service,  one-fifth  of  the  weight  of  the  projectile  is 
usied  for  a  charge  for  solid  shot,  spherical  case  and  shell  from 
guns  ;  for  canister,  one  sixth  of  its  weight ;  and  for  shell  ^nd 
case  shot  from  howitzers,  one-twelfth. 

The  French  at  one  time  used  chlorate  of  potash  in  the 
manufacture  of  gunpowder ;  but  it  was  soon  abandoned,  owing 
to  its  instantaneous  explosion,  as  no  piece  of  ordnance  could 
rfesist  its  effects. 

In  field  service,  the  cartridges  should  be  well  packed  in 
their  chests,  with  cotton  or  tow,  to  prevent  their  rubbing  or 
jolting  against  the  sides  of  the  chest,  as  thereby,  in  their 
transportation,  some  of  the  grains  of  each  cbarge  would  be 
liable  to  be  ground  to  dust,  and  its  efficiency  much  diminished. 
They  should  not  be  packed  so  tight  as  to  interfere  with  a 
hasty  removal  from  the  chest  should  ^occasion  require.  The 
friction  primers  should  be  carefully  packed  in  a  small  parper 
or  tin  box  with  cotton,  and  tied  so  as  not  to  come  loose  in 
traveling,  and  placed  in  the  tray  separate  from  the  powder. 
Of  course,  a  dozen  or  so  should  be  kept  in  the  tube  pouch 


GUNPOWDER.  17 

ready  for  immediate  use.  No  broken  cartridge  or  loose  pow- 
der should  be  permitted  in  the  chest,  as  it  is  an  established 
fact  that  powder  can  be  made  to  explode  by  the  impact  of 
a  hard  substance,  and  a  few  grains  being  between  two  balls 
brought  powerfully  together  by  a  sudden  jar  might  produce  a 
serious  explosion. 

The  ammunition  chests  should  be  opened  and  the  cartridges 
carefully  aired  and  sunned  on  every  dry  day  succeeding  damp 
weather. 


18  NOTES   ON   ARTILLERY. 


III. 

THE  SMOOTH  BORE   AND   THE    HOWITZER— THE 
•  CAUSE  OF  THEIR  DEVIATIONS. 

Military  writers  assert  that  explosive  hollow  projectiles  were 
used  from  1521  to  1580,  but  it  is  doubted  if  the  modern  bomb 
was  understood  at  that  period.  The  present  howitzer  is  an 
invention  of  the  Dutch  artillerists,  and  derives  its  name  from 
the  German  Hauhitz.  *  The  distinctive  characteristic  of  the 
howitzer  is  that  it  has  a  chamber  for  the  reception  of  the  cart- 
ridge. The  object  of  the  chamber  is  to  hold  the  small  cartridge 
in  position,  that  the  whole  explosive  force  may  be  exerted 
against  the  centre  of  the  ball.  Without  it  the  small  cartridge 
in  the  large  bore  would  be  displaced.  It  is  also  much  shorter 
than  other  cannon  of  the  same  calibre,  and  being  used  with 
charges  of  only  one-twelfth  the  weight  of  the  solid  ball,  it  is 
made  much  lighter,  not  requiring  a  great  thickness  of  metal 
to  resist  the  effects  of  explosion. 

From  the  gun  we  fire  solid  shot,  spherical  case,  shell  or 
canister  ;  but  from  the  howitzer  it  is  not  usual  to  fire  solid  shot, 
as  with  the  small  charge  of  powder  used,  on  account  of  limited 
amount  of  metal  at  the  breech,  but  little  initial  velocity  would 
be  given  the  ball.  The  metal  required  to  cast  a  12  pounder 
gun  put  in  the  form  of  a  howitzer,  enables  us  to  project  a  24 
pound  shell.  As  shells  are  effective  by  their  e^-plosion  and  not 
by  their  velocity,  it  is  no^  required  that  they  should  have  an 
initial  velocity  as  great  as  that  given  to  solid  shot. 

In  the  United  States  the  proportions  between  the  weight  of 


THE  SMOOTH  BORE  AND  THE  HOWITZER.        19 

the  b*all  and  the  gun  are,  in  the  12  pounder,  299  to  1 ;  in  the 
42  pounder,  201  to  1 ;  in  the  10  and  12  inch  columbiads,  137 
to  1.     In  brass  guns  the  proportion  is  147  to  1. 

Senderos  places  the  tenacity  or  cohesive  force  of  wrought 
iron  at  4234  atmospheres,  of  bronze  at  3872,  and  of  cast  iron 
at  1358  atmospheres;  while  Navier  places  the  cohesive  force 
of  wrought  iron  at  4164|  atmospheres,  of  bronze  at  2475,  and 
cast  iron  at  1307. 

We  thus  see  that  wrought  iron  is  the  strongest  material  for. 
guns,  bronze  next,  and  cast  iron  the  weakest.  From  the  diffi- 
culty of  constructing  wrought  iron  guns  that  material  has  not 
yet  been  successfully  used.  Bronze  guns,  composed  of  ten 
parts  tin  to  one  hundred  of  copper,  are  made  much  lighter  than 
iron  ones,  on  account  of  their  greater  tenacity,  and  hence  that 
material  is  used  for  field  pieces  when  it  can  be  obtained.  This 
is  the  only  advantage  that  bronze  guns  have  over  iron  ones, 
that  of  being  lighter;  while  for  long  use  and  rapid 'firing,  iron 
guns  are  superior  to  bronze,  as  we  shall  presently  see. 

The  difference  between  the  diameter  of  the  ball  and  the  bore 
of  the  gun,  called  windage,  varies  from  nine-hundredths  to 
sixteen-hundredths  of  an  inch.  On  account  of  this,  when  the 
ball  rests  in  the  bore  in  front  of  the  charge,  there  is  a  space 
in  the  upper  part  of  the  bore  above  the  ball  equal  to  the  wind- 
age. When  the  charge  is  fired  the  propellant  gas  escapes 
largely  by  this  unoccupied  space  above  the  ball,  and  wedges  it 
down  against  the  bottom  of  the  bore  with  great  power,  causing 
it  to  form  an  indentation  called  a  had.  When  the  gas  acting 
behind  the  ball  moves  it  forward,  it  does  not  move  in  the  direc- 
tion of  the  axis  of  the  piece,  but,  on  account  of  the  obstacle 
of  its  bed,  it  rises  upward  and  strikes  the  upper  part  of  the 
bore,  producing  a  burr,  called  a  lodgment ;  and  again  is 
thrown  down,  producing  another  lodgment^  forming  thus  two  or 


20  NOTES   ON   ARTILLERY. 

three  ricochets  in  the  bore  before  it  issjjes  from  the  muzzle. 
A  bronze  gun,  being  softer  than  the  cast  iron  projectile,  would, 
by  repeated  firing,  have  permanent  lodgments  made  in  its  bore, 
which  would  seriously  interfere  with  its  accuracy  of  fire,  and 
in  time  destroy  the  utility  t)f  the  gun.  When  a  gun  is  thus 
injured,  its  usefulness  is  in  a  manner  restored  by  lengthening 
the  sahot,  causing  the  ball  to  assume  a  new  hed.  A  bronze  gun 
"will  not  bear  rapid  firing,  since  when  the  metal  becomes 
€nuch  heated,  it  is  soft  and  the  gun  is  apt  to  droop  at  the  muzzle. 

Cast  iron  guns  are  not  injured  by  lodgments  on  account  of 
their  hardness,  nor  are  they  seriously  affected  by  rapid  firing. 
At  the  siege  of  Badajos  the  firing  continued  for  104  hours, 
and  the  number  of  rounds  that  each  gun  fired  averaged  1,249. 
At  the  siege  of  Sebastian  each  gun  averaged  350  rounds  in  15J 
hours.  "  The  guns  were  of  iron,  and  none  were  rendered  unser- 
viceable, though  three  times  the  number  of  brass  guns  would 
not  have  been  equal  to  such  long  and  rapid  firing." 

Experiments  have  shown  that  the  power  of  a  gun  to  resist 
explosion  increases  with  the  length  of  time  that  it  is  allowed  to 
remain  after  cast  before  it  is  used.  While  guns  cast  but  a  few 
days  have  burst  on  a  few  fires,  those  cast  for  thirty  years  have 
resisted  the  shock  of  more  than  2,000  rounds. 

These  deviations,  which  no  accuracy  of  aim  can  wholly  over- 
come, are  due  to  two  causes:  (1)  windage  or  difference  between 
the  diameter  of  the  ball  and  the  bore  of  the  gun ;  and,  (2) 
the  excentricity  of  the  centre  of  gravity  of  the  ball  or  shell. 
These  causes  do  not  act  separately,  but  the  deviation  is  gen- 
arally  the  resultant  of  the  two.  Numerous  experiments  were 
made  in  France,  as  recorded  in  the  Encyclopoedia  Britannica, 
to  observe  the  deviation  of  the  projectile  from  the  axis  of  the 
bore,  by  placing  a  screen  30  yards  in  front  of  the  muzzle. 

The  result  of  the  experiments  demonstrated  that  the  devi- 


THE   SATOOTH   BORE   AND   THE   HOWITZER, 


21 


ation  arising  from  the  two  causes,  though  not  always,  is,  gen- 
erally, an  elevation.  The  average  deviation  amounted  to  3  J  min- 
utes in  guns,  and  to  lOJ  minutes  in  howitzers — one-fourth  of 
the  shot  from  the  guns  having  an  elevation  of  more  than  8J 
minutes,  and  a  depression  below  the  axis  of  IJ  minutes.  In 
howitzers  one-fourth  had  an  elevation  of  more  than  15J  min- 
utes, and  one-fourth  5}  minutes  above  the  axis ;  the  remaining 
shots  passing  within  these  limits.  In  a  horizontal  direction 
half  of  the  shots  deviated  from  the  axis  more  than  4J  minutes 
to  the  right  or  left. 

The  author  of  the  article  "Artillery,"  in  the  new  American 
Encyclopoedia,  says  the  effective  range  of  field  guns  is  not  over 
1,500  yards,  at  which  distance  one  shot  out  of  six  or  eight 
might  be  expected  to  hit  the  mark.  The  decisive  ranges  in 
"which  alone  cannon  can  contribute  to  the  issue  of  a  battle  are 
for  round  shot  and  shell,  between  COO  and  1,100  yards,  and 
at  these  ranges  the  probability  of  striking  the  object  is  not 
very  great.  It  is  reckoned,  that  at  700  yards,  about  50  per 
cent. ;  at  900  yards,  about  35  per  (ffent ;  and  at  1,100  yards, 
about  25  per  cent.,  out  of  the"  shots  fired  from  a  6  pounder 
will  hit  a  target  representing  the  front  of  a  battalion  in  column 
of  attack,  (31  yards  long  by  2  yards  high). 

In  1850  experiments  in  France  with  8  and  12  pounders  gave 
the  following  results  against  a  target,  30  metres  by  3  metres, 
representing  a  troop  of  cavalry : 


Distance  in  metres,         .          ^    . 

500 

600 

700 

800 

900 

Per  cent,  of  12  pounder  hits, 

64 

54 

43 

37 

32 

Per  cent,  of  8  pounder  hits. 

67 

44 

40 

28 

28 

22  NOTES   ON   ARTILLERY. 

This  table  shows  the  superiority  of  a  12  pounder  over  a  6 
pounder  for  all  distances  over  550  yards.       • 

From  th^se  experiments  we  would  infer,  that  even  if  the 
centre  of  gravity  of  the  projectile  coincided  perfectly  with  the 
centre  of  magnitude,  still  there  would  be  considerable.deviation, 
depending  upon  the  angle  which  the  projectile  would  make  with 
the  axis  of  the  piece.  But  the  main  cause  of  the  deviation  is 
due  to  the  excentricity  of  fhe  projectile,  which  is  measured  by 
the  distance  between  the  centre  of  magnitude  and  the  centre 
of  gravity.  Owing  to  the  nature  of  the  .material  of  which 
projectiles  are  made,  it  is  almost  impossible  to  avoid  excen- 
tricity ;  consequently,  if  we  suppose  the  resultant  of  the 
propellant  gas  to  act  on  the  centre  of  form,  and  not  on 
the  centre  of  gravity,  by  a  simple  principle  of  mechanics 
it  follows,  that  the  ball  will  have  both  rotary  and  pro- 
gressive motion,  and  the  rotation  will  be  around  the  centre 
of  gravity.  This  rotation  may  be  further  modified  by  friction 
against  the  interior  of  the  bore.  Hence  we  may  safely  assert, 
that  every  round  projectife  fired  from  a  smooth  bore  gun  rotates 
around  some  axis.  If  this  axh  of  rotation  is  not  coincident 
with  the  line  of  fire,  the  projectile  will  be  deviated  from  its 
straight  course  by  the  inequality  of  the  resistance  of  the  air 
on  the  sides  of  the  revolving  projectile.  Suppose  the  axis  of 
rotation  of  the  ball  is  perpendicular  to  the  line  of  fire,  and  the 
ball  revolves  from  right  to  left,  it  is  obvious  that  the  resistance 
of  the  air  on  the  right  hemisphere  of  the  ball  is  due  to  the 
velocity  of  progression  added  to  that  of  rotation,  while  the 
resistance  experienced  by  the  left  half  is  due  to  the  velocity  of 
progression  diminished  by  that  of  rotation.  Hence,  under*  the 
circumstances,  the  right  half  would  have  a  greater  resistance 
acting  upon  it  than  the  left.  The  resultant  of  this  excess  of 
resistance  would  tend  "constantly  to  push  the  ball  to  the  left, 


THE   SMOOTH    BORE   AND   THE   HOV/ITZER.  23 

and  thereby  cause  deviation  from  the  line  of  sight  in  that 
direction. 

In  1737  Mr.  Robins,  in  his  numerous  experiments,  observed 
these  irregular  deviations,  and' assigned  these  deflections  "to 
the  oblique  action  of  the  resisting  medium  on  the  surface  of 
the  ball,  arising  from  its  rotary  movement." 

In  1771  Robins'  conclusions  received  a  remarkable  verifica- 
cation.  A  screen  was  placed  32  feet  from  the  muzzle,  and  a 
ball  which  pierced  the  screen  five-sixths  of  an  inch  to  the  right 
of  the  prolongation  of  the  axis,  at  a  range  of  3,765  yards, 
deviated  230  yards  to  the  left,  and  another  which  pierced  the 
screen  one  inch  to  the  left,  at  a  range  of  4,072  yards,  deviated 
230  yards  to  the  right.  These  anomalies  can  be  explained  only 
by  the  rotary  movement.  As  late  as  1838  the  subject  of  the 
excentricity  of  the  deviations  caused  thereby  was  not  generally 
understood,  as  is  admitted  by  General  Paixhans.  This  igno- 
rance of  an  importan-t  subject,  which  had  been  explained  one 
hundred  years  before,  is  by  no  means  complimentary  to  artil- 
lerists. 

We  take  the  liberty  of  quoting  upon  this  interesting  subject 
from  Dahlgreen's  Shells  and  Shell  Guns : 

"  The  doctrine,"  he  says,  *'  commonly  received  and  con- 
firmed by  experiment,  in  relation  to  excentricity  and  its  conse- 
quences upon  the  trajector}^  of  cannon  balls,  may  be  briefly 
summed  thus :  When  the  centre  of  gravity  does  not  coincide 
with  the  centre  of  the  sphere,  a  revolving  motion  is  created 
around  the  centre  of  gravity,  the  direction  of  which  depends 
on  the  position  that  the  centre  of  gravity  has  to  the  centre  of 
the  sphere.  This  rotation  during  the  flight  of  the  projectile 
occasions  a  greater  resistance  on  one  side  of  the  hemisphere, 
which  is  in  front,  tli.an  on  the^other;  because  on  the  former 
the  progressive  and  rotatory  motions  concur,  and  on  the  other , 


24  NOTES   ON   ARTILLERY. 

they  are  in  opposition.  Hence,  the  projectile  is  made  to  in- 
cline from  its  direct  course  by  the  greater  pressure  which  it 
sustains  on  one  side ;  and  the  aberration  thus  produced  will 
be  in  the  prolongation  of  the  plane  passing  through  the  axis 
of  the  bore  and  centre  of  gravity,  and  will  occur  on  the  same 
side  of  the  trajectory  as  the  centre  of  gravity  occupies  with 
respect  to  the  axis  of  the  bore. 

"  So  that  if  the  centre  of  gravity  be  in  the  vertical  plane, 
the  deflection  from  the  normal  trajectory  will  be  vertical  and 
upwards,  or  downwards,  accordingly  as  the  centre  of  gravity 
is  in  the  upper  or  lower  hemisphere.  If  above,  the  range  will 
be  increased ;  if  below,  decreased ;  by  the  very  conditions  of 
the  case,  and  without  lateral  deviation. 

"  If  the  centre  of  gravity  lie  in  the  horizontal  plane,  the 
deflection  will  be  entirely  lateral  and  right  or  left  as  the 
centre  of  gravity  may  lie.  If  the  centre  of  gravity  occupy 
some  position  between  the  vertical  and  horizontal  planes,  as  it 
commonly  does,  then  the  aberration  will  be  partly  vertical  and 
partly  lateral.  It  doe«  not  appear  that  the  location  of  the 
centre  of  gravity  in  the  anterior  or  posterior  hemisphere, 
materially  effects  its  operation ;  except  that  there  is  a  slight 
increase  of  range  where  the  centre  of  gravity  is  in  the  poste- 
rior hemisphere  and  in  the  axis  of  the  bore." 

Dahlgreen  found,  that  by  placing  this  centre  of  gravity  of 
an  excentric  ball  90°  up,  the  range  was  increased  nearly  200 
yards. 

We  will  conclude  the  notes  on  this  subject  by  mentioning 
some  facts  in  regard  to  the  ordnance  of  the  siege  of  Sevasto- 
pol, taken  from  the  report  of  Major  Mordecai,  of  the  Ord- 
nance Department. 

At  the  siege  of  Savastopd  no  cannon  of  extraordinary 
.  calibre  or  range,  no  breech-loading  guns,  no  rifled  cannon, 


THE  SMOOTH  BORE  AND  THE  HOWITZER.        25 

(except  the  Lancaster  gun,)  were  put  to  the  test  of  actual 
service.  Before  the  impromptu  fortifications  of  Sevastopol 
the  allies  placed  in  battery,  at  various  times  during  the  siege, 
more  than  2,000  pieces  of  heavy  ordnance,  besides  the  hun- 
dreds of  field  pieces  with  which  the  troops  were  armed.  The 
first  siege  train  with  which  the  French  army  presented  itself 
before  the  place  consisted  of  sixty  pieces  of  the  calibres 
usually  employed  in  such  operations,  16  and  24  pounder  guns, 
8  inch  howitzers,  and  8  and  10  inch  mortars.  These  being 
soon  found  insufficient,  were  followed  by  other  trains,  amount- 
ing to  250  pieces.  Many  guns  of  heavier  calibre  were  drawn 
from  the  fleet ;  but  the  armament  which,  at  last,  appears  to 
have  been  most  efficient  in  rendering  the  works  untenable  was 
a  train  of  mortars,  of  which  the  French  alone  had  120  thirteen 
inch,  the  same  number  of  ten  inch,  and  about  100  eight  inch. 
'Add  to  these  the  English  siege  train  of  more  than  900 
pieces,  consisting  chiefly  of  68  pounder  and  32  pounder  guns ; 
13  inch,  10  inch  and  8  inch  mortars  ;  a  considerable  quantity 
of  which  were  in  battery  at  the  close  of  the  siege,  and  some 
idea  may  be  formed  of  the  storm  of  shot  and  shell  which  was 
poured  upon  the  works  during  the  bombardment  of  three  days 
preceding  the  last  assault. 

"  The  appearance  of  the  ground  within  the  Malakoff"  and 
Redan  bastions,  after  the  retreat  of  the  Russians,  showed  the 
impossibility  of  serving  the  guns  of  the  palace  during  the 
bombardment.  It  was  scarcely  possible  to  plant  a  foot  on  a 
spot  on  the  terreplain  of  those  works  which  tvas  not  marked 
hy  a  cannon  hall,  or  hy  the  explosion  of  a  shell,  and  the  de- 
fenders could  only  remain  there  under  cover  of  their  bomb- 
proof shelters,  which,  although  mostly  constructed  rudely  of 
timber  fascines  and  earth,  seemed  to  have  generally  resisted 
the  fire  of  the  besiegers,''  • 


26  NOTES   ON   ARTILLERY. 

How  very  culpable  lia\^e  been  those  who  have  had  charge  of 
the  construction  of  our  fortifications  1  At  Sevastopol,  while 
under  a  fire  and  during  the  operation  of  the  siege,  the  Russian 
engineer  had  "bomb-proof  shelters  of  timber  fascines  •and 
earth"  constructed  in  the  fortifications,  which  afforded  a  safe 
protection  against  a  storm  of  shot,  and  shell  from  2,000  can- 
non during  three  days.  While  our  engineers  with  months 
before  them,  and  no  enemy  in  sight,  have  been  content  to 
build  open  pens,  which  have  surrendered  after  a  brief  struggle 
of  a  few  hours.  Let  our  generals  in  command  see  to  it  that 
our  engineers  have  work  done  with  no  enemy  to  molest,  at 
least  as  well  as  Totleben  had  constructed  under  the  galling 
fire  of  the  allies. 

"  The  number  of  pieces  of  ordnance  burst  at  Sevastopol  was 
small  in  proportion  to  the  whole  number  used.  But  it  was 
stated,  that  about  two-thirds  of  the  ordnance  used  in  the  siege 
was  considered  unserviceable  at  its  termination.  Many  of  the 
guns  had  been  rebouched ;  some  of  them  two  or  three  times ; 
some  bouchings  of  wrought  iron  were  tried,  but  did  not  last 
long.  The  French  siege  trains  were  supplied  with  1,500  to 
2,000  rounds  a  piece*;  their  batteries  fired  during  the  siege 
about  1,250,000  rounds  of  all  kinds,  and  at  the  close  there 
remained  fi«om  800  to  900  rounds  of  ammunition  for  each 
piece.  The  field  batteries  were  supplied  with  1,000  rounds 
for  each  piece." 

Of  all  the  guns  used  by  the  British  only  twelve  burst. 
Three  of  these  were  Lancaster  guns.  In  the  report  it  .is 
stated,  that  the  32  pounder  guns  fired  on  an  average  1,500 
rounds  each. 

Captain  Kennedy,  of  the  Royal  Navy,  says  in  his  report : 

"The  68  pounders  landed  from  the  *  Terrible'  were  con- 
stantly in  use,  and  I  slfould  say  the  least  number  of  rounds 


THE   SMOOTH   BORE   AND   THE   HOWITZER.  27 

fired  from  any  one  of  them  was  3,000 ;  some  of  them  went  up 
to  4,000.  They  were  fired  with  the  16  pounder  charge,  and 
frequently  very  rapidly." 

The  allies  found  in  Sevastopol  about  4,000  pieces  of  ord- 
nance of  all  kinds ;  but  the  number  of  unserviceable  pieces 
was  tivice  the  number  in  battery  !  Showing  that  the  guns  had 
been  several  times  renewed.  The  Russian  gunners  were  pro- 
tected from  sharp-shooters  with  the  rifle  by  a  mantlet,  made  of 
rope,  to  cover  the  embrasures. 

A  field-cannon  ball  will  disable  seven  or  eight  m^  at  a  dis- 
tance of  900  yards.  It  is  said,  that  at  the  battle  of  Zorn- 
dorfi*,  a  single  ball  disabled  forty-two  men. 


28  NOTES   ON   ARTILLERY. 


IV. 


THE  RIFLE  CANNON— "  DRIFT "  OF  THE  BALL, 
AND  ITS  CAUSE. 

It  is  stated  that  rifles  have  been  in  use  since  1600.  The 
principle  of  the  rifle  was  clearly  stated  by  Robins  in  1737, 
viz :  'that  as  the  deviation  of  the  ball  was  caused  by  the  un- 
equal pressure  of  the  air,  produced  by  its  revolution,  this 
cause  of  deviation  would  be  wholly  destroyed  by  causing  the 
ball  to  revolve  around  an  axis  coincident  with  the  line  of 
flight.  The  motion  of  rotation  being  at  right  angles  to  that 
of  progression  in  no  measure  influences  the  resistance  of  the 
air.  The  ball  is  caused  to  revolve  on  this  axis  by  "rifling" 
the  bore,  or  cutting  in  it  the  threads  of  a  female  screw.  The 
spherical  ball  was  used  with  the  rifle  for  many  years,  and  this 
with  the  diSiculty  of  loading,  (the  ball  necessarily  having  to  fit 
tight  to  take  the  threads,)  prevented  its  adoption  by  troops 
in  the  field. 

In  1829,  Delvigne  proposed  to  remove  the  difficulty  of  load- 
ing, by  flattening  a  smaller  ball  on  the  edge  of  the  chamber 
with  a  blow  from  the  ramrod.  Thouvenin  afterwards  proposed 
to  use  a  small  stem  projecting  from  the  breech  plug  into  the 
bore,  around  which  the  ball  was  to  be  flattened  by  the  ram- 
mer. Delvigne  afterwards  made  the  base  of  the  ball  flat; 
hence  the  conical  or  elongated  ball. 


•  THE   RIFLE   CANNON.  29 

Minie  afterwards  made  the  stem  of  Thouvenin  in  the  form  of 
a  cone  and  fixed  it  in  the  ball,  instead  of  the  breech  of  the  gun. 
This  culot^  by  the  propellant  gas,  (having  less  inertia)  was 
thrown  forward  into  the  ball  and  expanded  it  to  fill  the  bore. 
Afterwards  it  was  discovered  that  the  gas  acting  in  the  hollow 
cavity  of  the  ball  expanded  it  without  the  culot  of  iron.  Hence 
we  have  the  present  "  cylindro-conoidal  ball." 

W.  Greener,  of  London,  claims  priority  in  the  discovery  of 
what  is  now  called  the  "Minie  ball." 

About  thirty  years  ago  Cavalli  S.  WahrendofF  constructed 
breech  loading  rifle  cannon,  which  eventually  failed.  Later, 
Lancaster  introduced  his  rifle  cannon  of  elliptical  bore.  It  was 
like  a  smooth  bore  with  its  section  an  ellipse  instead  .of  a  circle; 
having  the  major  axis  of  the  ellipse  at  the  muzzle  at  right 
angles  to  the  major  axis  at  the  breech. 

Great  results  were  anticipated  of  the  Lancaster  guns.  They 
were  tried  at  the  siege  of  Sevastopol,  and  utterly  failed  to 
realize  the  expectations  previously  entertained.  Several  of 
them  burst  on  account  of  the  wedging  of  the  shot  in  the  bore, 
when  the  elliptical  shot  were  abandoned  and  they  were  fired 
with  spherical. 

The  principle  of  the  expansion  of  the  Minie  ball  was,  imme- 
diately after  its  application  to  small  arms,  applied  to  rifle  can- 
non. For  a  while  there  seemed  a  difficulty  in  attaching  the 
hollow  cup  of  soft  metal  at  the  base  to  the  metal  of  the  ball. 
This  difficulty  is  now  overcome,  and  the  elongated  ball  is  fired 
from  rifle  cannon  of  the  largest  bore.  It  has  been  found  by 
fastening  an  inverted  copper  saucer  at  the  hasp  of  the  ball 
the  windage  is  destroyed  and  the*  rotary  motion  given. 

In  the  examination  of  the  smooth  bore,  we  found  there  were 
two  principal  causes  of  deviation  in  the  ball,  windage  and  the 
excentricity  of  the  ball  causing  a  revolution  around  some  other 


5U  NOTES   ON   ARTILLERY. 

axis  than  that  coincident  with  the  normal  trajectory.  Both  of 
these  causes  of  deviation  are  entirely  eliminated  in  the  rifle 
cannon.  '  * 

By  the  action  of  the  gas  on  the  soft  metal  at  the  base  of  the 
ball,  it  is  expanded  to  fill  up  entirely  the  bore,  and  thereby 
cuts  off  all  escape  of  a  gaseous  fluid.  Hence  the  ball  is  pro- 
jected with  very  great  velocity,  as  all  the  propellant  gas  acts 
on  it,  and,  moreover,  its  elasticity  is  much  increased  by  thus 
confining  it  and  allowing  none  to  escape.  The  soft  metal  is 
thus  pressed  into  the  grooves,  and  as  the  ball  moves  forward 
it  acquires  a  rotatory  motion  around  an  axis  coincident  with  the 
axis  of  the  bore.  Hence  the  deviations  to  which  the  smooth 
bore  is  liable  are  entirely  obviated  in  the  rifle  cannon,  inas- 
much as  the  expansion  of  the  cup  cuts  off  the  escape  of  gas, 
and  thereby  prevents  lodgments  in  the  bore.  -The  ball  is  made 
cylindro-conoidal,  having  thereby  nearly  twice  the  weight  of  a 
sphere  of  same  calibre,  and  meets  with  much  less  resistance 
Crom  the  air.  Considerably  less  powder  is  required  to  give  a 
larger  ball  much  greater  range,  with  far  greater  accuracy,  than 
can  be  done  with  a  smooth  bore.  '  -*    » 

While  it  is  true  that  a  ball  from  a  rifle  cannon  is  not  liable 
to  the  enormous  and  irregular  deviations  of  a  smooth  bore,  yet 
it  is  found  bj-  practice  to  be  subject  to  another  deviation  peculiar 
to  itself.  It  is  found  that  the  ball  will  not  continue  to  move  in  a 
vertical  plane,  but  will  depart  from  it  towards  the  right,  if  the 
ball  is  revolving  from  left  to  right,  or  in  the  direction  of  the 
hands  of  a  watch  held  before  you.  If  the  revolution  of  the 
ball  is  in  the  contrary  direction,  the  departure  will  be  towards 
the  left.  This  deviation  of  the  rifle  ball  is  technically  called 
the  ''drift''  of  the  ball,  and  it  is  said  the  ball  "drifts"  in  the 
direction  in  which  it  revolves.  The  "drift"  only  takes  place 
with  the  elongated  ball,  and  the  amount  of  deviation  seems  to 


THE   RIFLE   CANNON.  31 

depend  on  the  range.  The  French  rifle  guns  used  in  the  Italian 
war  were  provided  with  a  graduated  lateral  slide,  by  means  of 
which  the  eflfect  of  this  deviation  was  corrected.  If  the  drift 
was  towards  the  right,  it  became  necessary  to  point  the  rifle 
towards  the  left  of  the  object,  which  was  done  by  sighting 
at  the  object  over  one  of  the  graduations  to  the  left  of  the 
vertical  tangent  right. 

Sufficient  number  of  experiments  have  not  yet  been  made 
with  our  guns  to  determine  the  amount  of  deviation  corres- 
ponding to  each  range,  and  without  these  experiments  we  do 
not  know  how  to  graduate  this  lateral  sight. 

The  Armstrong  gun  is  a  breech  lo-ading  rifle  cannon  of  small 
calibre,  with  a  bore  made  of  twisted  steel.  It  is  said  to  have 
remarkable  range  and  accuracy ;  that  it  may  confidently  be 
relied  on  placing  shot  after  shot  in  a  target  6  feet  square  at  a 
distance  of  3,000  yards.  The  "drift"  of  the  gun  is  always 
towards  the  right,  in  the  direction  of  its  revolution.  Colonel 
Jacob,  in  his  "Rifle  Practice,  London,  1858,"  denies  that  the 
deviation  of  the  ball  is  always  towards  the  right,  and  that  it 
is  generally  so,  he  attributes  to  the  fact  that  the  rifle  is  fired 
from  the  right  shoulder.  He  argues  that  the  breech  of  the 
rifle  resting  against  the  right  shoulder,  by  the  force  of  recoil, 
does  not  tend  to  move  backwards  in  the  prolongation  of  its 
axis,  but  tends  to  revolve  around  the  centre  of  gravity  of  the 
mass  of  the  hodj  and  rifle,  which  throws  the  muzzle  of  the 
rifle  slightly  towards  the  right  before  <he  ball  is  clear  of  the 
bore,  thus  causing  the  generally  observed  deviation.  He  further 
adds,  in  confirmation,  that  a  rifle  fired  from  the  left  shoulder 
will  deviate  towards  the  left.  The  Enfield  practitioners,  on 
the  contrary,  always  found  that  the  ball  deviated  towards  the 
right,  and  this  deviation  in  some  rifles  is  corrected  by  arrang- 


32  NOTES   ON   ARTILLERY. 

ing  the  breech  sight,  so  that  it  moves  towards  the  left  as  it  is 
elevated  to  increase  the  range. 

Lieutenant  Simons,  of  the  Bengal  Artillery,  in  his  "  Treatise 
on  Fire  Arms,  London,  1857,"  acknowledges  that  in  his  exper- 
iments he  observed  that  the  deviaticJn  was  in  the  direction  of 
the  revolution.  He  gives  an  explanation  similar  to  that  given 
by  Lieutenant  Gibbon  in  the  "Artillerist's  Manual."  The  axis 
of  the  elongated  ball  remains  in  its  flight  nearly  parallel  to 
itself,  and  is  not,  therefore,  always  tangent  to  the  trajectory 
described.  Hence,  when  the  axis  of  the  ball  makes  an  angle 
with  the  tangent  to  the  trajectory,  if  the  ball  is  revolving  from 
right  to  left,  the  portion  of  the  ball  on  the  right  side  meets 
with  a  greater  resistance  than  that  on  the  left,  as  a  part  of  its 
rotary  motion  on  that  side  coincides  with  its  motion  of  pro- 
gression. But  this  excess  of  resistance  on  the  right  side  would 
obviously  cause  the  ball  to  deviate  towards  the  left,  in  obedi- 
ence to  the  general  law,  that  a  body  left  free  to  obey  the  forces 
acting  upon  it  will  move  in  the  path  of  least  resistance.  And 
this  is  exactly  opposite  to  the  direction  in  which  experiment 
proves  that  it  does  deviate.  Now,  to  explain  why  it  will  deviate 
towards  the  right,  with  the  excess  of  resistance  on  the  right, 
.  Lieutenant  Simons  says,  by  reason  of  this,  the  point  of  the 
bullet  will  become  slightly  tipped  tow^ards  the  right,  and  then 
the  bullet  will  be  drifted  in  that  way  !  He  does  not  presume  to 
ofifer  an  explanation  why  it  is  that  the  point  of  the  bullet  will 
be  tipped  in  the  direction  in  which  experiment  proves  that  the 
drift  takes  place.  There  is  no  force  which  can  give  this  for- 
tunate tip  to  the  bullet-point,  and  hence  his  explanation  is 
wholly  unsatisfactory. 

Lieutenant    Gibbon,   if    the   writer    remembers    correctly, 
attempts  to  turn  the  point  in  the  proper  direction  by  assert-^ 
ing  that  this  excess  of  resistance  acts  only  on  the  rear  part 


THE   RllPLE    CANNON.  83 

of  the  ball,  about  the  centre  of  gravity,  and  throws  that  to  the 
left,  leaving  the  point  turned  towards  the  right.  This  simple 
assertion,  or  supposition,  has  no  reason  to  be  admitted,  but  the 
contrary,  and  therefore  cannot  be  received  as  a  philosophical 
explanation. 

Some  French  writer  asserts  that  the  "drift  "  is  due  to  the 
different  densities  of  the  strata  of  air  in  which  the  ball  (not  hori- 
zontal) is  revolving ;  that  owing  to  the  different  densities  the 
rear  part  of  the  ball  is  removed  farther  from  the  normal  tra- 
jectory towards  the  left  than  the  upper  part,  having  a  greater 
resistance  acting  on  it,  and  thus  the  ball  is  turned  with  its 
point  slightly  towards  the  right,  and  hence  drifts  as  observed. 

This  theory  of  the  different  densities  of  the  strata  of  air 
through  which  the  projectile  moves  is  unsatisfatory,  inasmuch 
as  the  ball  is  at  no  time  perpendicular  to  the  horizon,  and  the 
extreme  depth  of  the  strata  would  not  exceed  10  or  12  inches. 
And,  again,  owing  to  the  velocity  of  the  ball,  and  the  violent 
commotion  produced  in  the  air  around  it,  and  the  condensation 
of  the  resisting  medium  in  front  of  tjie  ball,  we  are  brought  to 
the  conclusion,  that  if  there  is  any  difference  in  the  densities 
of  the  strata  resisting  its  motion,  it  is  almost  inappreciable,  and 
is  wholly  inadequate  to  produce  the  deviation  observed. 

As  all  the  theories  mentioned  to  explain  the  "drift"  of 'the 
rifle  ball  are  altogether  inadequate  and  wholly  unsatisfactory, 
we  propose  an  explanation  entirely  different.  This  theory  of 
"drift"  at  least  has  the  merit  of  being  actually  tested,  and  if 
it  is  correct,  it  suggests  an  easy  method  of  preventing  "drift," 
and  of  thus  rendering  the  rifle  free  from  all  inaccuracy. 

The  forces  acting  on  an  elongated  rifle  ball  in  motion,  are 

similar  to  those  acting  on  the  gyroscope  when  put  in  motion, 

and  its  aberration  or  precession  is  exactly  similar  to  that  of 

the  gyroscope.     It  is  well  known  that  if  the  wheel  {q)  of 

3 


34  NOTES    ON   ARtlLLERY. 

the  gyroscope  is  made  to  revolve  rapidly  in  the  direction 
indicated  by  the  arrows,  and  the  axisj^  g,  perpendicular  to  the 
wheel  5',  is  rested  on  a  point  of  support  at  p,  the  excess  of 
weight  being  on  the  side  q,  the  wheel  q  will  gradually  move 


towards  a.  But  if  the  excess  of  weight  is  on  the  side  u\ 
thereby  leaving  a  resultant  to  draw  w  downwards,  and  the 
wheel  q  still  is  made  to  revolve  towards  the  right,  indicafed  by 
the  arrows,  then  q  will  move  towards  5,  or  the  whole  will  revolve 
around  p,  in  the  direction  in  which  the  wheel  q  revolves.  If 
the  weights  at  w  and  q  are  equal,  then,  by  revolving  g,  there 
will  be  no  motion  around  p.  Thes^  are  i\iQ  facts  of  the  action 
of  the  gyroscope.  It  is  not  designed  here  to  attempt  to  oiFer 
the  received  explanation  ;  suffice  it  to  say,  that  the  forces  which 
produce  this  apparently  anomalous  motion  are  similar  to,  those 
which  produce  the  retrogradation  in  the  line  of^nodes  of  the 
moon's  orbit,  and  the  precession  of  the  equinoxes ;  and  we  pro- 
pose to  make  the  "drift"  of  the  rifle  ball  subject  to  the  same, 
general  law. 

In  the  elongated  rifle  ball,  with  the  soft  metal  attached  to 
its  base,  the  centre  of  gravity  is  not  midway  between  the  axis 
of  the  cone  and  the  base,  but  is  nearer  the  base  of  the  ball. 
If  the  elongated  ball  is  placed  horizontally  in  any  supporting 


THE   RIFLE    CANNON. 


35 


medium,  it  will  be  found  that  the  centre  of  buoyancy,  as  the* 
resultant  of  all  the  buoyant  forces,  will  be  between  the  centre 
of  gravity  and- the  apex,  of  the  cone.  If  the  ball  is  placed 
horizontally  in  mercury,  the  base  of  it  will  sink  until  the 
resultant  of  the  buoyant  forces  passes  through  the  centre  of 
gravity.  If  it  is  placed  horizontally  in  air,  the  samfe  thing 
will  take  place  as  the  ball  begins  to  fell,  though  the  buoyant 
forces  will  be  less  in  the  ratio  of  the  density  of  mercury  to 
that  of  air.     Suppose  the  ball  represented  by  Fig.  2,  is  revolv- 


nD/^.^ 


ing  towards  the  right,  as  indicated  by  the  arrows,  ^,  the  centre 
of  gravity,  (the  ball  being  leaded  at  the  baseband  6,  the  centre 
of  buoyancy,  it  is  obvious  by  the  influence  of  gravity  and 
the  buoyant  force  of  the  air  there  will  be  a  tendency  for  the 
base  to  descend  and  the  apex  to  asceno^  or  a  tendency  to 
revolve  around  a  point  situated  between  g  and  5.  Now  con- 
fining the  attention  to  the  front  of  the  ball  revolving  towards 
the  right,  with  a  tendency  to  ascend,  it  will  be  seen  that  it  is 
acted  on  by  forces  similar  to  the  gyroscope,  (fig.  1)  when  the 
excess  of  weight  is  at  w ;  hence  it  will  move  in  a  similar  man- 
ner, or  the  point  of  the  ball  will  move  towards  the  right.     The 


36  NOTES    ON    ARTILLEEY. 

base  of  the  ball  is  revolving  towards  the  right,  with  a  tendency 
to  descend,  hence  it  is  acted  on  by  forces  similar  to  the  gyro- 
scope, (fig.  1)  with  the  excess  of  weight  at  the  wheel  q,  and 
the  base  therefore  will  recede  to  the  left.  By  this  analysis  we 
get  a  couple  which  tends  to  revolve  the  ball  horizontally,  with 
its  point  to  the  right.  It  is  true  these  forces  would  be  very 
slight,  but  still  sufficient  to  produce  the  "drift"  that  is 
observed.  Were  the  ball  revolving  towards  the  left,  a  similar 
analysis  would  show  that  the  tendency  was  to  turn  the  point 
to  the  left,  and  thus  cause  the  drift  in  that  direction. 

Of  what  practical  use  is  this  theory  of  the  cause  of  "drift?" 
We  propose  by  it  to  correct  tlife  only  inaccuracy  to  which  the 
rifle  ball  is  liable.  It. was  mentioned,  in  speaking  of  the  gyro- 
scope, (fig.  1)  that  when  the  weights  at  f  and  w  were  equal,  or 
when  the  instrument  was  exactly  supported  at  its  centre  of 
gravity,  there  was  no  tendency  to  move  either  to  right  or  left, 
no  matter  in  what  direction  the  wheel  q  revolved ;  consequently, 
if  our  theory  is  correct,  it  will  follow,  by  throwing  the  centre 
of  gravity  forward,  so  as  to  make  it  coincide  in  a  vertical  line 
with  the  centre  of  buoyancy,  there  will  be  no  tendency  what- 
ever in  the  rifle  ball  to  deviate  to  the  right  or  left.  If  the 
centre  of  gravity  is  thrown  (by  extracting  metal  from  the  base 
of  the  ball)  nearer  to  the  apex  than  the  centre  of  buoyancy, 
the  deviation  of  the  ball  will  be  in  a  direction  contrary  to  what 
is  now  observed.  To  sum  up,  we  affirm  that  if  a  rifle  ball  is 
so  constructed  that  it  will  float  horizontally  in  mercury,  it  will 
have  no  "drift."  If  opportunity  occurs  it  is  designed  to  test 
the  correctness  of  our  theory  by  actual  experiment. 

In  speaking  of  gunpowder,  we  endeavored  to  state  clearly 
the  reason  why  it  is  necessary  to  have  the  powder  for  guns  of 
large  calibre  of  large  grains.  The  inertia  of  rest  has  to  be 
overcome.     This  cannot  be  done  instantaneously ;  an  interval 


THE  RIFLE    CANNON.  •  37 

of  time  is  required.  Hence  with  large  grains  a  longer  interval 
of  time  is  required  to  consume  the  Avhole  charge,  and  the  pro- 
jectile is  -made  to  move  when  only  a  portion  of  the  charge  is 
converted  into  gas,  and  thus  it  receives  its  great  initial  velocity 
without  danger  to  the  gun.  Suppose  the  ball  is  not  sent 
home,  but  is  allowed  to  rest  in  the  bore,  say  one  foot  from  the 
charge,  the  result  will  be,  that  the  first  gas  generated  will 
not  act  to  move  the  ball,  but  to  condense  powerfully  the  air 
in  the  vacant  space.  The  whole  or  a  great  part  of  the 
charge  will  be  consumed,  and  gas  of  powerful  tension  be 
brought  to  act  on  the  ball  in  a  state  of  rest ;  this,  by  its  elas- 
ticity, will  rebound,  and  meeting  with  other  gas  of  powerful 
tension,  will  produce  a  powerful  strain  on  the  interior  of  the 
bore  of  sufficient  power,  it  may  be,  to  burst  it.  That  the  gas 
acts  in  this  way  to  burst  the  gun,  is  inferred  from  some  exper- 
iments in  which  the  ball  was  designedly  left  some  inches  from 
the  charge.  In  these  experiments  it  was  found  that  when  the 
tension  was  not  sufficient  to  burst  the  gun,  the  barrel  expanded 
in  the  form  of  a  ring,  not  exactly  at  the  ball,  but  a  few  inches 
nearer  the  breech.  Guns  have  been  known  to  burst  by  the 
muzzle  getting  accidentally  fii^d  with  clay  or  even  snow.  Ful- 
minates that  are  instantaneously  converted  ilito  gas  will  burst 
a  gun  without  the  assistance  of  a  ball.  The  inertia  of  the  air 
which  fills  the  bore,  resists  so  powerfully  the  rapid  movement 
of  the  gas,  that  its  whole  force  is  exerted  against  the  material 
of  the  gun,  which  cannot  withstand  its  effects. 

From  these  considerations  we  cannot  insist  too  strongly  upon 
the  great  importance  of  sending  the  hall  home  against  the  charge. 
Several  unfortunate  accidents  have  already  happened  in  our 
service  from  the  bursting  of  large  guns  ;  we  fear  some  of  them 
from  neglect  of  the  important  consideration  to  which  we  now 
allude.     This  is  especially  important  in  rifle  guns,  as  a  very 


38         •  NOTES   ON  ARTIiLERY. 

slight  flaw  in  the  bore  catching  the  soft  metal  of  the  cup,  may 
check  the  ball  before  it  is  home,  and  thus  deceive  the  rammer. 
This  may  happen  especially  in  the  percussion  rifle  shell,  which 
is  sent  home  by  the  rammer  with  great  caution  and  not  rapidly. 
The  unfortunate  results  attending  some  of  the  accidents,  teach 
us  that  too  great  caution  cannot  be  used.  The  bursting  of 
some  of  the  rifle  guns  was  no  doubt  caused  by  the  balls  becom- 
ing wedged  fast  in  the  bore.  The  ordnance  department  has 
•  attempted  to  avoid  this  by  a  new  arrangement  of  the  soft 
metal,  which  it  is  believed  will  be  successful. 

It  is  by  no  means  to  be  inferred  that  if  a  cannon  once  pro- 
jects, without  bursting,  a  ball  not  at  home^  it  will  do  so  a 
second  and  a  third  time.  The  shock  received  at  first  may  be 
just  sufficient  to  prepare  the  gun  for  bursting  under  similar 
conditions  on  the  second  or  third  fire. 

We  may  remark  just  here,  that  it  is  now  an  established 
fact,  that  the  devices  cast  upon  the  exterior  of  old  guns  seri- 
ously injured  their  powers  to  resist  the  explosion  of  the 
charge.  The  tendency  of  the  cast  metal  is  to  crystallize 
perpendicular  to  the  cooling  surfaces.  Hence,  our  guns  are 
ma'de  now  as  smooth  and  regulaac  as  possible  on  the  exterior. 
Steel  is  better  f(Jr  a  rifle  gun  than  iron  or  bronze,  inasmuch 
as  its  bore  will  admit  of  a  higher  finish,  and  hence  the  friction 
of  the  ball  will  be  much  diminished. 

RANGE  OF  THE  ARMSTRONG  GUN. 

The  Armstrong  gun,  4  inch  bore,  charge  3J  pounds,  weight 
of  ball  29  pounds,  has  the  following  ranges,  as  determined 
by  experiments  at  West  Point,  1860 : 


THE   RIFLE   CANNON. 


39 


• 

Elevation. 

• 

Range. 

Time. 

" 

Yards. 

5° 

2099 

7.5^^ 

7° 

2894 

9.P/ 

10° 

8700 

11.6^/ 

1  OO 

4\% 

14.2^/ 

15° 

4776 

17.1^^ 

20° 

6070 

21.4^^ 

25° 

6580 

25.0^^ 

30° 

7555 

31.0^/ 

35° 

9000 

DRIFT  OF  THE  RIFLE. 


The  mean  drift  of  40  sliots  fired  from  a  rifle  musket,  at  a 
distance  of  1,150  yards,  was  18  feet  to  the  right. 

The  following  important  table  gives  the  drift  of  the  French 
rifle  cannon  with  a  helix  of  4.37  feet: 


Range — in  yards 


Drift— in  feet  and  inches, 


2T§ 


.5" 


I'.l" 


437 


1.'9" 


2'.0" 


765    874 


4'.9",7'.6"|11'.6" 


r\ 


16M" 


1093 


21'.0" 


1312    1421 


38'.4"  56'.6" 

I 


This  shows,  that  for  a  range  of  1,421  yards,  the  drift  was 
as  much  as  50  feet  to  the  right.  A  deviation  which  it  is  im- 
portant for  the  gunner  to  provide  against  in  firing  rifle  cannon 
at  long  ranges. 


I 

40  •  NOTES   ON   ARTILLERY. 


RESISTANCE  OF  THE  AIR. 

Were  it  possible  to  project  a  ball  from  a  cannon  in  vacuOy  it 
would  be  acted  upon  by  tvro  forces :  the  impulsive  force  of  the 
propellant  gas,  and  the  constant  acting  force  of  gravity.  The 
spaces  through  which  gravity  would  draw  it  would  vary  as  the 
squares  of  the  times,  or  as  the  squares  of  the  spaces  through 
which  it  would  pass,  acted  on  solely  by  the  impulsive  force. 
This  mathematical  consideration,  from  the  known  relation 
existing  between  the  abscissa  and  ordinate  of  the  parabola, 
clearly  demonstrates  th'at  the  trajectory  of  the  ball,  acted  on 
solely  by  these  forces,  would  be  a  parabola.  But  the  supposi- 
tion is  a  case  that  "is  impossible  to  exist.  Instead  of  having 
only  two  forces,  the  impulsive  force  and  the  force  of  gravity, 
there  acts  on  every  ball  projected  from  a  gun  a  third  force  of 
powerful  influence,  which  modifies,  in  a  remarkable  manner, 
its  trajectory,  and  causes  it  to  be  no  longer  a  parabola,  but  a 
curve,  wliich  somewhat  assimilates  to  that,  in  the  first  portion 
of  the  path  described.  This  third  force  is  the  resistance 
which  the  air  ofi*ers  to  the  passage  of  the  projectile  through  it. 

In,  the  early  calculations,  this  force  was  entirely  neglected. 
All  calculations  were  made  on  the  supposition  that  the  tra- 
jectory was  a  parabola.  The  discrepancy  existing  between 
theory  and  practice  induced  Sir  Isaac  Newton  to  give  it  his 
attention.  He  inferred  the  law  that  the  resistance  was  pro- 
portional to  the  square  of  the  velocity,  and  calculated  the 
ranges  for  that  basis.     The  science  of  gunnery  thereby  re- 


RESISTANCE   OF   THE   AIR.  41 

ceived  considerable  advance,  but  still  it  was  far  from  perfec- 
tion. Mr.  Robins  undertook  the  most  elaborate  experiments 
on  this  subject  that  were  ever  performed  before  or  since. 
They  extended  through  many  years.  His  experiments  estab- 
lished beyond  a  doubt,  that  the  resistance  of  the  air  for  very 
great  velocities^  increased  in  a  far  greater  ratio  than  that  of 
the  square  of  the  velocity.  The  following  considerations  will 
lead  us  to  the  same  inference.  Air  rushes  into  vacuum  with  a 
velocity  of  from  1,200  to  1,300  feet  per  second.  Now,  when 
a  ball  is  moving  with  a  velocity  greater  than  this,  say  1,600 
feet  per  second,  there  is  a  vacuum  formed  behind  it ;  hence,  the 
pressure  of  the  air,  15  pounds  to  the  square  inch,  is  removed 
from  the  rear  of  the  ball,  but  exists  in  front.  Again,  as  the 
ball  mpves  forward  more  rapidly  than  the  air  can  move  aWay, 
the  atmosphere  must  be  powerfully  condensed  in  front  of  tho 
ball,  and  by  its  increased  density  and  elasticity  add  power- 
fully to  the  resistance. 

Consequently,  a  ball  moving  with  very  great  velocity,  equal 
to  the  initial  velocity  of  a  rifle  ball,  meets  with  a  wall  of  con- 
densed air  in  front,  and  is  entirely  relieved  of  pressure  in  the 
rear.  Hence,  when  the  ball  movdfe  #ith  a  velocity  greater 
than  1,300  feet,  there  is  another  element  of  resistance  brought 
into  action  which"  rapidly  augments  the  resistance  Sbove  that 
attained  from  the  law  of  the  duplicate  ratio  of  the  velocity. 

It  is  the  generally  received  law,  that  for  small  velocities  the 
resistance  offered  by  any  fluid  is  as  the  square  of  the  velocity. 
But  it  remained  for  Robins  to  determine  the  cause  of  the  diff'er- 
ence  between  practice  and  the  theory  of  Sir  Isaac  Newton,  and 
to  show  at  what  particular  stage  of  the  velocity  the  ordinary 
assumed  law  of  resistance  underwent  its  modification.  Robins 
determined  by  his  experiments  that  the  resistance  of  the  air 
on  tjie  surface  of  a  bullet  three-fourths  of,  an  inch  in  diameter, 


^  NOTES   ON   ARTILLERY. 

I  with  a  velocity  of  1,650'  feet,  amounted  to  as  much  as  a  weight 
of  10  pounds.  An  iron  ball  24  pounds  weight,  ,with  a  velocity 
of  1,650  feet,  has  a  resistance  of  540  pounds.  He  supposed 
that  the  change  in  the  resistance  of  the  air  was  very  suddenly 
increased  when  the  projectile  attained  the  velocity  of  air 
passing  into  vacuum,  and  that,  however  great  the  initial  velo- 
city of  the  ball  might  be,  it  would,  within  the  first  500  yards 
of  range,  be  reduced,  on  account  of  the  powerful  resistance, 
to  a  velocity  of  1,200  feet  per  second. 

Robins  gives  the  following  rules  for  calculating  the  resist- 
ance of  air  to  projectiles  : 

1.  If  the  velocity  of  the  projectile  is  less  than  1,100  feet 
per  second,  the  resistance  varies  as  the  square  of  the  velocity, 
and  its  mean  quantity  is  a  half  ounce  avo^irdupois  ork  a  12 
pound  shot  moving  with  a  velocity  of  25  or  26  fe^t  per 
second. 

2.  If  the  velocity  is  greater  than  1,100,  then  the  resistance 
is  three  times  as  great  as  it  would  appear  to  be  by  the  first 
rule. 

Prof.  Robinson  gives  the  following  rule  to  find  the  velocity 
with  which  a  ball  must^  m*ove  to  meet  with  a  resistance  from 
the  air  equal  to  its  own  weight : 

Rule.— ^Multiply  the  diameter  of  the  ball  in  inches  by  300. 
The  product  will  be  the  space  in  yards^  through  which  the  ball 
must  fall  in  vacuum  to  actfuire  the  velocity  which  will  cause 
it  moving  through  air  to  m.eet  with  a  resistance  equal  to  its 
weight. 

This  rule  is  determined  from  a  mathematical  formula.  Call- 
ing this  space  s,  we  have  for  velocity  acquired  in  falling  through 
this  space  2;  =  2  j/ 16  s  =  8  |/  s.  The  resistance  correspond- 
ing to  ^\/  s  =  w,  its  weight.     Hence, 

(8i/7.)2     :     v'^    :i     W    :     x, 


RESISTANCE   OF   THE   AIR.  43 

• 

when  X  is  the  resistance  corresponding  to  v'.  For  velocities 
exceeding  1,200,  Zx  will  be  the  true  value  of  the  resistance. 

An  application  of  the  above  principles  gives  the  following 
amounts  : 

A  6  pounder  ball  (3.58  inches  diameter),  with  a  velocity  of 
1,650  feetji  meets  with  a  resistance  equal  39  times  its  weight, 
or  234  pounds.  , 

A  12  pounder  ball  (4.51  mches  diameter),  with  a  velocity  of 
1,650  feet,  meets  with  a  resistance  equal  30  times  it  own 
weight,  or  360  pounds. 

A  24  pounder  ball  (5.68  inches  diameter),  with  a  velocity 
of  1,650  feet,  meets  with  a  resistance  equal  26  times  its  own 
weight,  or  624  pounds. 

A  32  pounder  ball  (6.25  inches  dfameter),  with  a  velocity 
of  1,650  feet,  meets  with  a  resistance  equal  23  times  its  own 
weight,  or  736  pounds. 

.  A  42  pounder  ball  (6.84  inches  diameter),  with  a  velocity  of 
1,650  feet,  meets  with  a  resistance  equal  21  times  its  weight, 
or  882  pounds. 

A  64  pounder  ball  (7.88  inches  diameter),  with  a  velocity  of 
1,650  feet,  meets  with  a  resistance  equal  18  times  its  weight, 
or  1,152  pounds. 

An  130  pounder  ball  (9.88  inches  diameter)  with  a  velocity 
of  1,650  feet,  meets  with  a  resistance  equal  15  times  it  weight, 
or  1,950  pounds. 

These  are  the  resistances  on  spherical  balls,  and  are  enor- 
mous. In  view  of  the  great  amount  of  this  resistance,  it  has 
occurred  to  the  writer  that  it  is  possible,  by  giving  the  ball  a 
proper  shape,  to  convert  a  portion  of  this  resisting  force  into 
a  force  to  produce  rotation.  It  has  not  yet  been  done.  Still 
he  has  such  confidence  in  his  theoretical  examination  of  the 
subject  as  to  feel  satisfied  that  the  next  improvement  in  gun- 


44  NOTES   ON  ARTILLERY. 

nery  -will  be  to  rifle  the  hall  instead  of  the  gun.  He  has  pro- 
posed for  trial  to  the  Ordnance  Department  two  methods,  one 
of  which  depends  on  the  principle  of  reaction,  or  inequality 
of  pressure  of  the  air  passing  in  an  orifice  in  front  of  the  ball 
and  escaping  by  small  tangential  orifices  near  the  circumfer- 
ence. Experiment  alone  must'  be  the  final  test  of  the  merit 
of  these  suggestions. 

Upon  the  supposition  that  there  is  fio  resisting  medium,  we 
find  by  calculation  that  a  ball  projected  at  an  angle  of  45°, 
with  a  velocity  of  1,600  feet,  would  have  the  extreme  range 
of  twenty-one  miles  !  Whereas  in  practice  we  know  it  ranges 
but  little  over  three  miles. 

Wilcox,  in  his  "  Rifle  and  Rifle  Practice,"  gives  the  forms 
of  nearly  one  hundred  different  shaped  balls,  formed  for  the 
purpose  of  diminishing  to  the  least  degree  the  resistance  of 
the  air,  and  of  producing  the^  greatest  accuracy.  On  this  sub- 
ject Major  Mordecai  says,  "  the  paraboloid  fulfills  in  the 
highest  degree  every  requisite,  as  here  all  the  deviated  ele- 
ments produced  backward  form  focal  lines,  and  unite  at  the 
focus.  This  form  also  secures  the  greatest  divergence  of  the 
deflected  air  currents,  and  consequently  the  least  opposition 
from  the  resistance  of  the  air." 


FUZES.  45 


.      VI. 
FUZES. 

Shells,  whenifirst  used,  were  fired  from  mortars,  and  lighted 
bj  the  hand  just  before  the  charge  was  exploded.  It  was  after- 
wards discovered  that  the  flame  of  the  escaping  gas  was  suffi- 
cient to  produce  ignition.  They  are  called  time  fuzes,  and 
concussion  or  percussion,  according  as  they  explode  by  the 
fuze  being  ignited  by  the  flame,  or  by  coming  in  contact  with 
a  resisting  object.  The  old  wooden  fuze  plugs,  with  mealed 
powder  in  paper  for  a  time  fuze,  are  still  used,  only  instead 
of  having  diff*erent  lengths  of  fuze  to  burn  different  times, 
the  same  length  is  made  to  burn  5,  10  or  15  seconds,  by 
giving  to  the  mealed  powder  different  degrees  of  pressure. 

The  Bormann  fuze,  now  so  well  known,  and  used  in  all  our 
field  pieces,  possesses  thegreat  advantage  of  having  the  press- 
ure applied  horizontally  to  the  mealed  powder,  and  thereby 
causing  equal  lengths  of  the  juze  to  burn  in  equal  times. 
Some  of  the  first  issued  from  the  Ordnance  Department  were 
not  well  screwed  in  the  shell,  and  consequently  many  burst 
very  near  the  muzzle,  if  not  in  the  gun,  no  matter  for  how 
many  seconds  they  were  cut.  The  writer  conceived  that  this 
premature  explosion  was  in  a  measure  due  to  the  flame  passing 
between  the  thread  of  the  screw  and  the  shell,  and  had  the 
fuzes,  of  all  the  shells  in  the  battery  to  which  he  was  attached, 
screwed  in  as  tight  us  possible  with  the  fuze  wrench,  and  then 


46  NOTES   ON   ARTILLERY. 

had  the  space  around  the  exterior  rim  of  the  fuze  very  closely 
glazed  with  a  mixture  of  white  lead  and  litharge.  When  this 
glazing  hardened  he  had  the  satisfaction,  on  subsequent  trials, 
of  witnessing  very  few  premature  explosions.  If  the  metal  is 
cut  away  so  as  to  expose  a  surface  as  large  as  the  fourth  of  a 
half  dime,  explosion  will  take  place.  Of  course  the  fuze  end 
of  the  shell  is  placed  towards  the  muzzle ;  if  towards  the ' 
charge,  the  violent  explosion  of  the  powder  would  drive  the 
fuze  into  the  shell  and  cause  it  to  burst  in  the  gun. 

The  Splingard  concussion  fuze  consists  of  j§ hollow  cone  of 
gypsum,  with  its  base  to  the  interior  of  the  shell,  and  its  exte- 
rior firmly  packed  around  with  mealed  powder.  This  mealed 
powder  burns  during  the  flight,  and  when  the  shell  strikes,  the 
cone  is  unsupported,  and  is  broken  by  the  shock,  when  the  flame 
is  communicated"  to  the  interior  and  produces  explosion.  It  is 
said  to  have  acted  well  on  trial. 

The^^  English  Navy  percussion  fuze,  invented  by  Captain 
Moorsom,  has  three  brass  hammers  suspended  by  wire  in  cav- 
ities in  the  shell.  Opposite  the  ends  of  these  hammers  is  placed 
fulminating  powder  communicating  with  the  shell.  The  shock 
of  the  shell  striking  is  supposed  to  break  the  hammers,  or  one 
of  them,  from  the  fastenings,  and  cause  the  explosion  by  im- 
pact against  the  fulminate. 

The  French  Navy  percussion  shell,  invented  by  Captain 
Bilbette,  has'  a  breaker  of  iron  attached  to  a  steel  screw,  and 
to  the  breaker  is  attached  a  chord  passing  through  chlorate  of 
potash  and  sulphuret  of  antimony.  By  the  shock  the  steel 
screw,  to  explode  the  shell,  must  break,  when  the  cord,  drawn 
through  the  substances  mentioned,  causes  explosion. ' 

The  writer  has  submitted  a  model  of  a  percussion  fuze,  which 
has  met  the  approval  of  the  Ordnance  Department.  It  is 
adapted  both  to  the  round  and  elongated  shell,  and  is  regarded 


FUZES.  ^  4T 

as  superior  to  that  adopted  by  the  English  and  French  Navy, 
inasmuch  as  it  is  easier  of  construction,  of  less  cost,  and  will 
more  certainly  explode.  For  hand-grenades  it  seems  perfectly 
adapted. 

The  rifle  shell  fuze  explodes  by  the  momentum  of  a  small 
mass,  upon  which  is  placed  a  percussion  cap,  striking,  when 
the  shell  is  suddenly  checked,  against  the  cover  of  the  fuze. 
It  is  said  to  act  well  when  the  shell  strikes  point  foremost. 

Sir  Howard  Douglas  asserts  that  "  a  percussion  shell  cannot 
be  lodged  in  the  wood  if  the  percussion  apparatus  performs  its 
function,"  and  Commander  Dahlgreen  remarks  that  it  does 
not  appear  that  this  has  been  satisfactorily  demonstrated,  and 
considers  it  an  "open  question."  Colonel  Jacob,  in  his  exper- 
iments, demonstrated  that  it  was  no  longer  an  "  (^pen  ques- 
tion," but,  "  that  the  comparatively  sloio  ignition  of  the  gun- 
'poivder  alloivs  the  shell  to  penetrate  deeply  before  bursting.'' 
He  regarded  his  "percussion  rifle  shells  as  the  most  formidable 
missile  ever  invented  by  man."  They  consist  of  a  copper  tube 
filled  with  powder  thrust  into  a  deep  opening  cast  in  the  fore 
end  of  the  bsHll.  The  end  of  the  tube  is  tipped  with  percus- 
sion powder,  and  the  tube  held  in  the  ball  with  resinous  cement. 
With  these  shell,  fired  from  his  rifle.  Colonel  Jacob  exploded 
caissons  at  a  distance  of  1,200  and  even  1,800  yards  I  He 
regards  it  possible  for  two  good  marksmen,  afn:ied  with  his  rifle 
and  these  shell,  to  annihilate  a  battery  of  field  artillery  in  a 
short  time,  at  a  distance  of  1,000  or*l,200  yards ;  and  his  own 
successful  experiments  seemed  to  render  his  assertion  by  no 
means  improbable. 


48  NO^^ES   ON  ARTILLERY. 


VII.  •  • 

SIGHTING  GUNS— HOW  TO  MAKE  SIGHTS. 

The  problem  of  sighting  a  gun,  at-  present,  (thanks  to  the 
theoretical  investigations  and  the  thousand  experiments)  is 
exceedingly  simple.  Everything  has  been  done  for  the  gunner 
before  he  goes  into  the  field.  The  initial  velocity,  depending 
on  the  weight  of  the  ball  and  the  charge  of  powder,  being 
fixed,  there  remain  two  other  variable  elements  to  determine 
the  trajectory  of  a  solid  shot,  the  range  and  the  angle  of  ele- 
vation, one  of  them  being  given  the  other  can  be  deter- 
mined. In  the  casef  of  a  shell,  we  find  three  variable  elements, 
range,  elevation  and  time,  two  of  which  must  be  known  to 
determine  the  other.  But  the  gunner  is  not  required  to  solve 
any  mathematical  equations.  Tables,  carefully  prepared  from 
theory  and  experiment,  giving  the  elevation,  range  and  .time  of 
flight  for  each  calibre,  are  published,  and  it  is  only  required  of 
the  gunner  to  make  an  intelligent  use  of  them.  These  tables 
will  be  found  in  the  last  section  of  these  notes. 

The  breech  of  the  cannon  is  larger  than  the  muzzle,  and  if 
a  line  be  drawn  from  the  breecli  to  the  muzzle,  it  will  not  be 
parallel  to  the  axis  of  the  bore,  but  makes  an  angle  with  it. 
Hence  the  line  of  metal  is  not  parallel  to  the  axis  of  the  bore. 

The  difi'erence  betweeen  the  radii  of  the  muzzle  and  the 
breech  is  called  the  ''^dispart,''  Every  gun  should  have  a 
muzzle  sight,  which  should  be  made  exactly  equal  to  the  dis- 


SIGHTING   GUNS.  49 

part.  The  dispart  is  foimd  thus :  measure  with  a  graduated 
tape  carefully  the  circumference  of  the  muzzle  and  of  the 
breech.  The  circumference  divided  by  3.1416  will  give  the 
diameter.  Half  the  difference  between  the  diameters  thus  cal- 
culated will  be  the  dispart. 

The  muzzle  sight  equal  to  the  dispart,  would  enable  the 
gunner  readily  to  make  the  axis  of  the  bore  horizontal,  by 
sighting  directly  at  the  object,  when  in  the  same  horizontal 
plane,  and  thus  secure  a  rolling  fire.  But  our  guns  are  not 
usually  made  with  muzzle  sights,  and  to  bring  the  axis  hori- 
zontal, it  is  necessary  to  depress  the  muzzle,  so  that  the  line  of 
sight,  along  the  line  of  metal,  produced,  shall  pierce  the  hori- 
zontal plane  about  100  yards  in  advance  of  the  piece.  The 
angle  between  the  line  of  metal  and  the  axis  of  the  bore  is 
usually  one  degree,  and  for  angles  of  elevation  greater  than 
one  degree,  the  muzzle  sight  gives  no  peculiar  advantages. 

The  lateral  direction  of  the  gun,  in  a  field  piece,  is  best 
given  by  seizing  the  trail  tandspike.  Standing  in  that  posi- 
tion, the  sight  can  be  better  corrected.  It  has  occurred  to  the 
writer  that,  possibly,  considerable  accuracy  and  facility  of  aim 
might  be  given  to  a  field  piece,  by  having  a  lateral  screw,  to 
work  by  the  hand,  fixed  near  the  elevating  screw,  so  as  to  give 
the  gun  motion  to  the  right  or  left  of  about  one  degree.  This 
might  be  done  by  attaching  the  cheeks  to  a  wrought  iron  plate, 
fastened  to  the  trail  stock  by  a  belt. 

If  it  happens  that  the  guns  are  not  provided  with  breech  sights, 
tangent  scales  or  pendulum  hauses,  as  did  occur  in  the  writer's 
case,  the  gunner  can  construct  for  himself  a  tangent  scale  which 
will  answer  all  his  purposes.  Measure  accurately  the  length  of 
the  gun  from  the  muzzle  sight,  or  highest  point  of  the  muzzle, 
to  the  base  ring ;  multiply  this  length  in  inches  by  the  natural 
tangent  of  one  degree  (.01746.)  The  product  will  be  the 
4 


50 


NOTES    ON   ARTILLERY. 


■■TP- 


riG,B. 


length  of  the  tangent  corresponding  to  one  degree  for  that 
gun.  Now  have  a  piece  of  mahogany  or 
walnut  prepared  of  shape  of  figure  3,  with 
one  straight  edge,  and  curvature  at  bottom 
to  fit  the  base  ring  of  the  gun,  and  lay  off 
on  this  the  distances  corresponding  to  a 
tangent  of  one  degree.  If  the  dispart  is 
equal  to  tangent  of  one  degree,  the  first 
space  laiiJ  off  must  be  marked  2°,  the  next 
3°,  &c.  Subdivide  these  spaces  into  equal 
parts,  and  we  have  the  tangents  of  a  quarter 
of  a  degree.  Now  prepare  a  small  square 
slide  about  one  inch  long  and  a  half  inch 
wide,  to  hold  between  the  thumb  and  finger 
of  the  left  hand.  If  the  distance  requires 
an  elevation  of  3°,  place  the  slide  on  the  tangent  scale  at  the 
line  marked  III,  hold  the  scale  vertical,  or  rather  perpendic- 
ular to  the  bore,  which  is  done  by  a  broad  bore  fitting  firmly 
on  the  base  ring,  and  sight  over  the  top  of  the  slide  and  muz- 
zle at  the  object;  taking  care  that  the  straight  edge  of  the 
tangent  scale  coincides  with  the  mark  on  the  base  ring  denoting 
the  highest  point  of  the  breech.  In  the  absence  of  a  slide, 
the  thumb  of  the  left  hand  may  be  used  to  sight  over,  or 
notches  may  be  cut  at  the  marks.  This  form  of  sight  may  be 
used,  or  a  circular  breech  sight  of  wood  serves  an  excellent 
purpose.  Immediately  opposite  (in  the  tangent  scale,  or  under- 
neath in  the  breech  sight),  the  marks  of  degrees  and  quarter 
degrees  there  should  be  placed,  in  conspicuous  figures,  the  dis- 
tance corresponding  to  that  elevation  for  solid  shot ;  also,  in 
another  column,  inarked  "spherical  case,"  there  should  be  put 
the  distance  and  time  of  flight  corresponding  thereto,  and  in 
the  same  manner  for  shell. 


SIGHTING   GUNS.  51 

The  gunner  thus  constantly  has  his  table  before  him.  He 
judges  of  the  distance  by" the  eye,  and  immediately  opposite 
that  distance  his  tangent  scale  tells  him  what  elevation  to  use ; 
and  if  he  desires  to  use  spherical  case  or  shell,  he  has  recorded 
just  by  the  distance,  the  time  to  cut  the  fuze  by.  With  this 
arrangement,  the  gunner  guesses  at  nothing  but  the  distance 
of  the  object.  The  time  and  elevation  corresponding  to  each 
distance  are  recorded  on  his  scale  ready  to  hand,  and  it  is 
only  concerning  the  distance  about  which  he  is  called  upon  tq 
form  a  judgment.  Hence  the  great  importance  of  having  the 
eye  trained  to  judge  accurately  of  distances. 


INSTRUMENTS  TO  DETERMINE  DISTANCES. 

Two  classes  of  instruments  have  been  proposed  for  deter- 
mining distances,  one,  measures  the  visual  angle  and  the  other 
superposes  images.  The  French  stadia  is  simply  a  graduated 
rule,  held  vertically  at  a  fixed  distance  from  the  eye,  say  two 
feet.  To  use  it,  the  top  of  the  stadia  is  brought  tangent  to 
the  ray  of  light  from  the  head  of  the  man  observed,  and  the 
thumb  nail  or  a  slide  moved  up  until  it  is  tangent  to  the  ray 
of  light  from  the  feet.  And  the  mark  indicated  on  the  stadia 
will  be  the  distance  required.  We  suppose  that  the  average 
height  is  5  feet  10  inches,  and  graduate  the  stadia  by  the  pro- 
portion of  similar  triangles,  thus,  2  feet  :  distance  on  stadia  :  : 
600  yards  :  5  feet  10  inches.  This  proportion  gives  about 
^ne-thirteenth  of  an  inch  for  the  graduation.  So  the  gradua- 
tion for  other  distances  can  be  determined.  This  stadia  may 
be  graduated  for  cavalry,  as  well  as  infantry. 

"Corporal  Malphet's"  instrument  depends  on  the  same 
principle.     It  is  composed  of  a  cylindrical  metallic  tube,  hav- 


52  NOTES   ON   ARTILLERY. 

ing  a  hole  at  one  end  to  apply  the  eye.  A  second  cylinder 
of  smaller  diameter  is  placed  within  the  first,  opened  to- 
•wards  the  eye,  an4  closed  at  the  other  end  by  a  circle  in 
which  is  cut  a  narro'w  transversal  slit.  The  inner  cylinder  is 
fastened  to  the  exterior  by  an  index  working  in  a  longitudinal 
slat.  When  the  instrument  is  applied  to  the  eye,  the  inner 
cylinder  is  moved  until  the  two  edges  of  the  transversal  slit 
become  tangent  to  the  object  at  its  extremities.  Then  the 
apparent  height  corresponding  to  the  distance  of  the  object  is 
found  marked  by  th^  index  against  the  graduations  of  the 
longitudinal  slat. 

But  instruments  cannot  be  relied  on,  especially  in  the  ex- 
•  citement  of  action.  The  eye  must  be  trained  by  practice  to 
judge  correctly  of  distances.  It  should  be  a  part  of  the  daily 
drill  in  a  field  battery  for  all  the  commissioned  and  non-com- 
missioned officers  to  practice  the  eye  in  judging  distances. 
To  do  this  a  soldier  should  be  placed  at  a  distance  of  100, 
200,  300,  400,  500,  &c.  yards  up  to  1,000  or  more.  At  each 
hundred  yards  all  should  be  called  on  to  observe  what  part  of 
the  uniform  is  visible  and  what  indistinct.  Each  should  care- 
fully .record  in  his  note-book  opposite  every  hundred  yards 
what  part  of  the  uniform  or  person  is  distinctly  visible  at  that 
distance.  These  notes  will  constitute  his  standard  of  com- 
parison, and  will  be  difi*erent  for  eyes  of  difierent  powers. 
Cavalry  should  be  noticed  as  well  as  infantry.  When  this 
has  been  done  frequently  and  each  is  familiar  with  his  own 
standard,  a  soldier  should  be  placed  9.t  an  unknown  distance^ 
and  each  required  to  note  down  the  amount  in  his  judgment. 
Then  the  distance  should  be  measured,  and  the  same  thing 
tried  for  other  distances.  Astonishing  accuracy  is  said  to  be 
attained  in  this  way  by  the  French  engineers.  And  the  confi- 
dence and  skill  acquired  by  an  officer  with  this  training  indi- 


SIGHTING   GUNS.  '  63 

cates  clearly  that  it  is  the  duty  of  each  to  apply  himself  to 
the  drill  in  this  respect. 

The  tables  of  efevation  and  ranges  given  in  the  Appendix 
are  the  result  of  thousands  of  experiments  made  with  the 
powder  used  in  the  old  United  States  service.  The  powder 
used  now  by  ourselves  is  probably  not  so  strotig,  as  our  own 
experiments,  carefally  made,  showed  that  one-fourth  of  a  de- 
gree must  be  added  to  the  elevation  to  secure  the  range  oppo- 
site in  the  tables. 


• 


54  ^       NOTES   ON   ARTILLERY. 


VIII. 

CLASSES  OF  PROJECTILES— CLASSIFICATION  OF 
FIRES— WHEN  EACH  SHOULD  BE  USED. 

There  are  fiVe  differeri^  classes  of  projectiles  used,  solid 
shot,  shell,  spherical  case,  grape  and  canister;  and  the  fires 
may  be  reduced  to  four  kinds,  direct,  plunging,  rolling  and 
ricochet.  A  direct  fire  is  when  the  object  is  struck  directly 
by  the  projectile  before  it  comes  in  contact  with  lyiy  other 
object.  A  flunging  fire  is  when  the  object  is  struck  by  tlie 
projectile  in  the  descending  branch  of  the  trajectory.  A 
rolling  fire  is  w4ien  the  axis  of  the  piece  is  made  horizontal, 
and  the  projectile  makes  several  ricochets  before  meeting  the 
object.  .  A  ricochet  fire  is  when  the  ball,  fired  at  a  low  range 
of  elevation,  strikes  the  ground  or  water  in  front  of  the  object 
and  rebounds.  There  are  three  things  necessary  to  be  known 
before  we  can  determine  what  projectile  and  what  kind  of  fire 
to  use:  "1st,  the  distance  of  the  enemy;  2d,  the  conforma- 
tion of  the  ground;  and  3d,  the  formation  of  the  enemy." 

As  a  general  rule,  solid  shot  are  used  only  against  troops 
in  masses ;  shell  and  spherical  case  against  scattered  troops, 
but  not  against  troops  in  motion ;  canister  used  only  when  the 
enemy  is  not  mt)re  than  400  yards  distant. 

When  a  charge  is  being  made  on  the  battery,  canister 
should  be  used  as  rapidly  as  possible.  After  the  distance  is 
diminished  to  400  yards,  and  when  very  near  the  battery,  two 


CLASSES   OF   PROJECTILES.  55 

cases  of  canister,  fired  at  once  from  a  single  chargC}  may 
repulse  the  enemy  and  save  the  guns.  Grape  shot  are  fired 
from  large  guns  under  circumstances  similar  to  those  in  which 
canister  are  fired  from  fixed  pieces. 

For  a  fire  against  troops  in  masses  a  ricochet  or  rolling  fire 
is  always  to  be  preferred,  if  the  ground  is  level  and  hard,  and 
thereby  favorable.  • 

When  a  shell  explodes,  the  splinters  are  acted  upon  by  two 
forces,  the  remaining  force  of  shell  moving  in  its  trajectory, 
which  acts  only  in  one  direction,  and  the  force  of  the  explo- 
sive charge  in  the  shell,  which  acts  in  every  direction.  The 
fragments  will  move  in  the  -direction  of  the  resultant  of  these 
two  forces.  Some  will  move  forward  with  a  velocity  due  to 
the  sum  of  these  two  forces ;  others  in  an  oblique  direction ; 
others,  laterally;  and  some,  if  the  force  of  explosion  is  greater 
than  that  of  progression,  will  have  a  retrograde  movement. 

A  shell  is  designed  to  produce  its  effect  mainly  by  the  force 
of  explosion,  and  not  by  the  force  of  progression.  Hence  the 
endeavor  should  be  to  explode  it  amongst  the  troops  of  the 
enemy,  and  not  in  front  of  them,  unless  it  be  the  object  to 
produce  a  moral  effect  alone ;  then  the  shell  should  be  made  to 
explode  in  front,  and  it  is  all  important  to  observe  this.  It  is 
better  always  for  the  shell  to  explode  too  soon,  instead  of  too 
late,  as,  though  tli£  physical  effect  may  be  lost,  the  moral  13 
secured.  And  it  is  a  generally  received  rule  among  military 
writers,  in  comparing  those  forces  which  serve  to  retard  the 
progress  of  the  enemy,  that  the  moral  is  to  the  phj^sical  as 
three  to  one. 

Spherical  case  constitute  the  most  formidable  projectile  in 
the  hands  of  an  artillerist.  A  spherical  case  for  a  24  pounder 
howitf  er  contains  175  musket  bullets.  These  are  compressed  in 
a  small  space,  enclosed  in  a  case  of  iron,  and  thus  projected  as 


56  NOTES   ON   ARTILLERY. 

a  solid  ball  for  a  distance  of  1,000  or  1,500  yards,  meeting  with 
the  least  possible  resistance  from  the  air.  By  the  explosion  of 
the  charge  within,  these  bullets  ar6  expanded  over  a  considera- 
ble area,  and  have  an  effect  as  destructive  as  that  of  a  com- 
pany of  infantry  immediately  in  front  of  the  enemy. 

The  charge  of  powder  within  this  projectile  is  very  small, 
only  sufficient  to  break  the  caee  and  well  expand  the  bullets. 
The  effect  is  due  to  the  velocity  of  progression 'entirely ;  hence 
a  spherical  case  s.hould  always  be  made  to  explode  50  or  75 
yards  in  front  of  the  enemy,  and  at  from  20  to  50  feet  eleva- 
tion, so  as  to  allow  the  cone  of  expansion  of  the  bullets  to 
cover  the  largest  possible  area. 

Ttie  rolling  or  ricochet  fire  should  always  be  used  when  the 
character  of  the  ground  will  admit  of  it,  as  it  not  only  increases 
the  dangerous  space,  but  has  a  moral  effect  in  addition  to  the 
physical.  If  the  troops  are  in  line  and  not  in  bodies,  a  ricochet 
fire,  striking  15  feet  in  front,  will  pass  completely  over  them. 
If  the  battery  is  above  the  object,  a  plunging  fire  alone  can  be 
used ;  and  if  a  fortification  is  to  be  destroyed,  the  direct  fire 
must  be  used,  taking  care  with  a  flanking  piece  to  endeavor  to 
enfilade  the  terre-plein  of  the  enemy's  works. 

•  When  the  ground  is  rough  and  hilly,  and  the  enemy  are  not 
in  close  masses,  shell  and  case  shot  must  always  be  used  in 
preference  to  solid  shot.  « 

Too  much  importance  cannot  be  given  to  the  first  fires  of  a 
battery.  If  fired  badly,  with  too  great  elevation,  the  enemy 
is  encouraged  to  advance  by  the  shell  bursting  in  his  rear.  If 
fired  well,  he  may  be  deterred  by  a  few  shots.  At  the  battle 
of  Manassas  an  instance  occurred  in  which  a  brigade  of  the 
enemy  was  'driven  back  by  four  well  directed  case,  shot  from 
one  of  our  6  pounder  batteries.  • 

It  is  saiii  that  all  young  artillerists  fire  too  rapidly,  and 


CLASSES   OF   PROJECTILES.  57 

thereby  throw  away  much  of  their  ammunition.  The  rule  is, 
■fire  slowly  and  cautiously^  and  observe  well  the  effect  of  the 
shot.  Benton  says  once  or  twice  a  minute  is  as  often  as  a 
field  piece  can  be  fired  and  aimed  well,  and  that  eleven  or 
twelve  times  an  hour  is' as  often  as  heavy  garrison  guns  can  be 
fired  with  success.  It  is  said  to  have  rarely  happened  that  a 
field  battery,  well  served,  has  used  the  ammunition  of  all  its 
chests  in  any  one  pitched  battle ;  and  it  is  somewhere  stated 
that  fifty  rounds  to  a  piece  is  as  much  as  was  used  in  Mexico 
in  any  engagement. 

When  any  o:P  the  following  conditions  are  fulfilled,  Benton 
says  shells  should  be  employed  in  preference  to  solid  shot : 

1.  When  the  enemy  is  stationary. 

2.  When  the  ground  is  much  broken. 

3.  When  the  troops  are  posted  in  woods. 

4.  From  one  mountain  to  another. 

5.  When  the  enemy  is  posted  on  higher  ground. 

6.  When  in  a  road  leading  through  a  rolling  country. 

7.  For  incendiary  purposes. 

8.  In  pursuit. 

9.  Whenever  it  is  necessary  to  produce  a  moral  rather  than  a 
physical  effect. 

When  shell  are  desigr^d'for  incendiary  purposes,  some  of 
the  powder  of  the  charge  should  be  removed,  and  pieces  of 
port-fire,  half  an  inch  long,  inserted  in  its  stead. 

It  should  be  observed  that  you  cannot  make  a  ricochet  fire 
with  a  rifle  cannon.  The  rotation  of  the  ball  acting  on  the 
surface,  diverts  it  immediately  from  its  normal  trajectory;  and 
it  often  happens,  for  a  similar  reason,  that  a  spherical  ball, 
from  a  smooth  bore,  is  diverted  from  its  direct  course  by  a 
ricochet  on  water. 


.58  NOTES    ON   ARTILLERY. 


IX. 

MISCELLANEOUS  MEMORANDA. 

CARE  OF  HORSES. 

As  the  whole  efficienc;^  of  a  field  battery  depends  in  a  great 
degree  upon  the  condition  of  the  horses,  too  great  care  of  them 
cannot  be  taken.  At  regular  hours  of  the  day  the  feeding  and 
grooming  should  be  done  in  the  presence  of  all  the  sergeants 
and  at  least  one  commissioned  officer.  The  drivers  should  not 
be  allowed  to  cease  grooming  until  the  drum  taps,  which  should 
be  at  least  half  an  hour  after  beginning.  Each  sergeant 
should  see  that  the  horses  of  his  teams  are  all  fed  and  well 
groomed,  as  without  this  close  scrutiny  they  will  deteriorate. 

It  would  be  well,  also,  to  select  some  one  man  of  most  expe- 
rience with  horses,  and  appoint  him  supervisor  of  stables.  It 
should  be  his  business  to  make  a  daily  report  to  the  Captain  of 
the  general  health  of  the  horses,  and  to  use  the  proper  means 
to  restore  any  that  are  diseased. 

TO  GUARD  AGAINST  THE  ENEMY'S  FIRE. 

In  the  field,  as  soon  as  it  is  discovered  that  the  enemy  has 
obtained  your  range,  the  pieces  should  be  moved  laterally  or 
^  forward,  from  40  to  50  yardsj  and  the  fire  rapidly  resumed. 
If  sharp-shooters   are   observed   in  the  neighboring  woods 
they  must  be  driven  out  with  shell. 


MISCELLANEOUS  MEMORANDA.  59 

If  the  guns  are  mounted  in  a  fort  en  barbette,' smd  the  can- 
noneers are  annoyed  by  sharp-shooters,  they  should  be  pro- 
tected by  sand  bags,  thus  forming  on  the  parapet  an  embra- 
sure. 

In  going  into  battery  on  the  field,  advantage  should  be 
taken  of  any  rise  in  the  ground.  If  the  carriages  are  placed 
just  behind  the  crest  of  a  hill,  with  the  guns  pointing  ove!"  it, 
great  protection  will  be  given  the  cannoneers,  as  all  ricochet 
shots  of  thg  enemy  will  rebound  entirely  over  the  piece.  This 
will  occur  even  with  a  small  hillock  two  feet  high. 

If  the  gun  is  in  a  fort  it  is  better  to  serve  it  with  five  men, 
.and  possibly  it  may  be  tetter  to  use  this  number  in  the  field, 
holding  the  others  in  reserve ;  as  thereby  fewer  men  are 
exposed.  In  this  drill,  with  five  men  besides  the  gunner,  Nos. 
2  and  5  interchange  in  carrying  the  load,  No.  3  performs  the 
duties  of  Nos.  3  and  4,  save  the  gunner  acts  as  vents-man  and 
No.  4  stands  at  the  limber  and  delivers  ammunition. 


PENETRATION  OF  SHOT. 

An  80  pound  rifle  shot  has  been  known  to  pass  through  7 
feet  of  masonry  at  a  distance  of  1,032  yards. 
At -200  yards  a  rifle  bullet  penetrates  11  inches  of  pine  board. 
At  600      "  *'  "         "  6j»        "         "         " 

At  1,000  "  "  "         "    .         31        "        "        " 

"  A  rope  mantlet,  3J  inches  thick,  as  used  by  the  Russians, 
will  resist  small  arm  projectiles  at  all  distances." 

Colonel  Jacob  mentions  an  experiment  in  which  a  ball  from 
his  rifle  was  fired  through  20  inches  of  deal  boards  and  buried 
itself  a  whole  length  in  a  block  of  hard  wood. 

In  Dahlgreen's  experiments,  shot  from  a  32  pounder,  at  a 
distance  of  1,000  yards,  penetrated  a  mass  of  seasoned  white- 


60  NOTES   ON  ARTILLERY. 

oak  the  depth  of   25  inches;    shot  from  a  64   pounder,  the 
depth  of  37  inches. 

PENETRATION  IN  IRON. 

The  late  engagement  at  Hampton  Roads  between  the  two 
iron-clad  vessels,  th?  Virginia  and  Monitor,  demonstrated  that 
a  succession  of  thick  iron  plates  offers  a  better  resistance  to 
shot,  than  a  solid  mass  of  equal,  thickness.  It  i^  said  that 
"while  the  turret  of  the  Monitor,  composed  of  eight  layers, 
each  an  inch  thick,  was  only  indented  2J  inches  by  a  shot 
striking  square  and  flat  upon  it,  one  of  the  solid  bars  or  plates, 
nine  inches  thick  and  12  inches  deep,  forming  a  part  of  the 
pilot  house,  was  completely  broken  in  two  by  a  similar  shot 
and  opened  f  of  an  inch  on  the  back  side." 

Various  experiments  were  made  in  England  to  test  the  resist- 
ance of  iron-clad  vessels  to  the  Armstrong  and  Whitworth  pro- 
jectiles, and  to  68  pound  shot.  The  result  maji  be  stated  to 
be  that  4  J  inch  iron  plates,  supported  behind^  are  proof  against 
shells,  hot  shot  and  cast  iron  shot,  68  pounders ;  that  they 
have  been  penetrated  by  wrought  iron  8  inch  shot  at  200 
yards,  and  by  the  Whitworth  projectile,  a  wrought  iron  bolt  3 
inches  in  diameter,  at  the  distance  of  400  yards.  Vessels 
clad  with  iron  plates  4J  inches  thick,  were  considered  safe 
against  ordinary  projectiles  at  a  distance  of  200  yards.  With 
this  view  the  French  Emperor  has  built  an  iron-clad  ship  of 
war,  "Le  Gloire,"  carrying  38  rifled  50  pounders,  and  England 
has  built  a  rival  to  "Le  Gloire,"  in  the  Warrior.  ^ 

The  rotating  cupola  of  the  "Monitor"  is  an  invention  of 
Captain  Cowper  Coles,  R.  N.  It,  we  learn,  is  clad  with  plates 
8  or  9  inches  thick. 

The  day  of  wooden  war  vessels  is  now  numbered  among  the 


MISCELLANEOUS  MEMORANDA.  61 

things  of  rtie  past ;  wrought  iron  in  future  will  be  the  great 
«  means  of  defence.  At  present  the  art  of  attack  bj  water, 
with  iron-clad  steamers,  is  superior  to  the  art  of  defence.  The 
relation  between  water  attack  and  land  defence  has  changed, 
the  inferior  has  become  the  superior,  and  wrought  iron  plates 
have  caused  it.  But  the  art  of  defence  can  resume  its  old  rela- 
tion of  superiority  to  that  of  attack,  in  one  way — by  increas- 
ing theealihre  of,  the  guns.  We  want  more  15  and  20  inch 
guns  to  smash  the  iron  sides  of  the^steamers  that  bid  defiance 
to  the  guns  that  now  guard  our-  forts.  We  venture  to  assert 
that  our  present  32  pounders,  42  pounders,  and  even  68  pound- 
ers .will  have  to  be  cast  into  15  and  even  20  inch  guns,  before 
*  our  seacoast  fortifications  can  be  said  to  be  secure. 

POWER  OF  LEADEN  BALL  TO  PENETRATE  IRON. 

We  are  not  aware  that  any  experiments  have  been  made  on 
the  powers  of  lead  to  penetrate  iron.  Theory  would  be  against 
it ;  but  Mr.  Greener,  of  London,  mentions  a  curious  experi- 
ment that  he  made  :  A  leaden  ball  punched  a  hole  through  a 
half-inch  boiler  plate,  Vhen  an  iron  ball,  under  the  same  cir- 
cumstances, rebounded  without  any  eflfect. 


62 


NOTES   ON   ARTILLERY. 


X. 


TABLES  OF  EANGES  AND  ELEyATIONS. 

The' following  tables  are   taken  from  the.  experiments  of 
Dahlgreen,  as  recorded  in  the  "  Shells  and  Shell  Guns:" 

Ranges  of  shot. 

32  Pounder  of  27  Cwt. 

BOUE  OF  GUN  SEVEN  FEET  ABOVE  WATER. 


Charge. 

Elevation. 

Range. 
1st  Graze. 

Lbs. 

o 

Yards. 

4 

1 

545 

2 

800 

3 

1047 

4 

1278 

5 

1469 

6 

1637 

TABLES   OF  RANGES  AND   ELEVATIONS. 


63 


32  Pounder  of  32  CwU^ 

SEVEN   AND    A   HALF    FEET   ABftVE    WATER. 


Charge. 

Elevation. 

1st  Graze. 

Lbs. 

o 

Yards. 

4i 

1 

581 

2 

857 

3 

1140 

4 

1398 

5 

1598 

32  Pounder  of  42  CwL 


GUN    EIGHT   AND    ONE-THIRD    FEET   ABOVE    WATER. 


Charge. 

Elevation. 

1st  Graze. 

Lbs. 

o      . 

Yards. 

5 

1 

616 

2 

913 

3 

1194 

4 

1420 

5 

1651 

64 


NOTES    ON   ARTILLERY. 


♦  32  Pounder  of  57  Ciot. 

GUN  NJNE  FEET  ABOVE  WATER. 


Charge. 

Elevation. 

1st  Graze. 

Lbs. 

o 

Yards. 

Q 

1 

770 

2 

1154 

3 

1449 

4- 

1708 

5 

1032 

6 

2144 

10 

2731 

RANGES  OF  SHELLS. 


8  Inch  0/55  Cwt. 

GUN  SEVEN  AND  A  HALF  FEET  ABOVE  "WATEfe. 


Charge. 

Elevation. 

1st  Graze. 

Lbs. 

o 

Yards. 

7 

1 

579 

2 

869 

3 

1148 

4 

1413 

5 

1657 

6 

1866 

8 

2315 

10 

2600 

TABLES   OF   RANGES   AND   ELEVATIONS. 


6fii 


8  Inch  of  63  Cwt. 

i 

NINE  FEET  ABOVE  WATER. 


Charge. 

Elevation. 

1st  Graze. 

Lbs. 

o 

Yards. 

9 

1 

662 

2 

966 

3 

1264 

.  4 

1540 

5 

1769 

RANGES  OF  MOUNTAIN  HOWITZERS. 

The    following    tables    are    taken    from    the    "  Ordnance 
Manual: " 


Charge, 

Projectile. 

Elevation. 

Range. 

Time. 

Lbs. 

o       / 

Yards. 

// 

0.5 

Shell, 

0 
1 

2 

170 

300 

•  392 

2  30 

500 

••     2 

3 

637 

4 

785 

3 

5 

1005 

Q.5 

Sph.  case, 

0 

150 

' 

2  30 
3 

450 
500 

2 

4 

700 

2.7 

• 

4  30 

800 

3 

0.5 

Canister, 

4  to  5° 

250 

66 


NOTES    ON  ARTILLERY. 


RANGES  OF  FIELD  GUNS  AND  HOWITZERS. 

The  range  of  a  shot  or  shell  in  this  table  is  the  first  graze 
of  a  ball  on  horizontal  ground,  the  piece  being  mounted  on  its 
appropriate  field  carriage. 

The  range  of  a  spherical  case  shot  is  the  distance  at  which 
the  shot  bursts*  near  the  ground  in  the  time  given ;  thus  show- 
ing the  elevation  and  length  of  fuze  required  for  certain  dis- 
tances. 


Kind  of  Ordnance. 

Powder. 

Ball. 

Elevation. 

Range. 

Remarks. 

Lbs. 

o      / 

Yards. 

6  Pdb.  Field  Gun, 

1.25 

Shot 

0 

318 

(S 

1 

674 

t< 

2 

867 

<t 

3 

1138 

l( 

4 

1256 

a 

5 

1523 

1. 

Sp.  case 

2 

650 

Time  flight,  2  sec 

shot 

2  30 

840 

u        (c     3  (t 

« 

3 

1050 

ec          tf      4   « 

12  Pde.  Field  Gun, 

2.5 

Shot 

0 

347 

« 

1 

662 

(( 

1  30 

785 

« 

2 
3 

909 
1269 

(C 

4 

1455 

t( 

5 

1663 

1.5 

Sp.  case 

1 

670 

Time,  2  seconds. 

(( 

1  45 

950 

ii      3        a 

a 

2  30 

1250 

((     4      (( 

TABLES   OF   RANGES   AND   ELEVATIONS. 


67 


RANGES  OF  FIELD  GUNS  AND  EOYfUZE^S— Continued, 


Kind  of  Ordnance. 

.  Powder. 

Ball. 

Elevation. 

Range. 

Remarks. 

Lbs. 

o      / 

Yards. 

12  Pdr.  Field  How- 

1. 

Shell 

0 

195 

itzer. 

(( 

1 

539 

it 

2 

640 

» 

(C 

.3 

847 

cc 

4 

975 

u 

5 

1072 

0.75 

Sp.  case 

2  15 

485 

Time,  2  seconds. 

(( 

3  15 

715 

(I      3       (c 

(t 

3  45 

1050 

«       4        cc 

24  Pdr.  Field  How- 

2. 

Shell 

0 

295 

itzer. 

it 

1 
2 
3 

516 
793 
976 

<( 

(C 

4 
5 

1272 
1322 

1.75 

Sp.  case 

2 

600 

Time,  2  seconds. 

(e 

3 

800 

cc       3         cc 

(( 

5  30 

1030 

cc       4        cc 

2. 

C( 

3  30 

880 

cc       3        cc 

32  Pdr.  Field  How- 

2.5 

Shell 

0 

290 

itzer. 

a 

a 
e< 

1 
2 
3 
4 
5 

531 

779 

1029 

1203 

1504 

♦ 

2.5 

Sp.  case 

3 

800 

Time,  2.75  sec'ds. 

68 


KOTES  ON  ARTILLERY. 


RANGES  OF  HEAVY  ORDNANCE. 


The  range  of  a  gun  or  howitzer  in  this  table  i$  the  first- 
graze  of  the  ball  on  the  horizontal  plane  on  which  the  carriage 
stands. 


Kind  of  Ordnance. 

Powder. 

Ball. 

Elevation. 

Range. 

Remarks. 

Lbs. 

0       / 

Yards. 

18  Pdr.    Siege    and 

4.5 

Shot' 

1 

641 

Garrison  Gun. 

(( 

2 

950 

On  barbette  carriage. 

(( 

3 

1256 

« 

4 

1450 

(C 

5 

1592 

24   Pdr.    Siege    and 

6. 

Shot 

0 

412 

Garrison  Gun. 

(C 

1 

842 

On  siege  carriage. 

i( 

1  30 

953 

11 

2 

1147 

« 

3 

1417 

(( 

4 

1666 

it 

5 

1901 

8. 

(( 

I 

883 

(( 

2 

1170 

(C 

3 

1454 

« 

4 

1639 

tc 

6 

1834 

32  Pdr.  Sea-Coast 

6. 

Shot 

1  45 

900 

Gun. 

8. 

ei 

1 

713 

On  barbette  carriage. 

« 

1  30 

800 

<( 

1  35 

900 

_ 

(( 

2 

1100 

* 

(( 

3 

1433 

<e 

4 

1684 

<• 

(( 

5 

1922 

» 

10.67 

(t 

1 

780 

t( 

2 

1155 

tc 

3 

1517 

' 

TABLES  OF   RANGES  AND   ELEVATIONS. 


69 


RANGES  OF  HEAVY  ORDNANCE— {7on«mwerf. 


Kind  of  Ordnance. 

Powder. 

Ball. 

Elevation. 

Range. 

Remarks. 

.Lbs. 

o       / 

Yards. 

42   Pdr.   Sea-Coast 

10.5 

Shot 

1 

775' 

Gun. 

<( 

2 

1010 

On  barbette  carriage. 

« 

3 

1300 

4< 

4^ 

1600 

(( 

5* 

1955 

, 

14. 

({ 

1 

770 

it 

2 

1128 

ti 

3 

1380 

i( 

4 

1687 

(C 

5 

1915 

Shell 

8  Inch  ^eige  How- 

4. 

45  lbs. 

0 

251 

itzer. 

(I 

1 

435 

On  siege  carriage. 

(( 

2 

618 

(C 

3 

720 

i( 

4 

992 

(( 

5 

1241 

t( 

12  30 

2280 

Shell 

8  Inch   Sea-Coast 

4. 

45  lbs. 

1 

405 

Howitzer. 

(( 

2 

652 

On  barbette  carriage. 

(( 

3 

875 

(( 

4 

1110 

<( 

5    ' 

1300 

6. 

({ 

1 

572 

(( 

2 

828 

^ 

<( 

3 

947 

. 

4k 

t( 

4 

1168 

(( 

5 

1463 

# 

8. 

« 

1 

646 

a 

2 

909 

, 

(( 

3     ' 

1190 

a 

4 

1532 

<( 

5 

1800 

Shell 

10  Inch   Sea-Coast 

12. 

90  lbs. 

1 

580 

Howitzer. 

u 

2 

891 

Time  flight,  3.  sec. 

On  barbette  carriage. 

u 

3 

1185 

cc            ((     4          (( 

(t 

3  30 

1300 

« 

4 

1426 

"        ««    5.25" 

(( 

5 

1650 

"        «    6.      " 

70 


NOTES   ON  ARTILLERY. 


RANGES  OF  HEAVY  ORDNANCE— Cow«mM«<f. 


Kind  of  Ordnance. 

Powder. 

Ball. 

Elevation. 

Range. 

Remaeks. 

Lbs. 

Shot 

o      / 

Yards. 

8  Inch  Columbiad. 

10. 

65  lbs. 

1 

932 

Axis  of  gun  16  feet 

On  barbette  carriage. 

(( 

2 

1116 

above  the  water. 

(( 

3 

1402 

* 

(I 

4 

1608 

• 

t( 

5 

1847 

• 

(( 

6 

2010 

(( 

8 

2397 

Shot  ceased  to  ric- 

(C 

10 

2834 

ochet  on  water. 

i( 

15 

3583 

({ 

20 

4322 

a 

25 

4875 

(( 

27 

4481 

15. 

(I 
Shell 

^7  30 

4812 

10. 

50  lbs. 

1 

919 

a 

2 

1209 

(C 

3 

1409 

IC 

4 

1697 

C£ 

5 

1813 

(( 

6 

1985 

it 

8 

2203 

* 

(C 

10 

2657 

(t 

15 

3556 

a 

20 

3716 

(S 

25 

4387 

cc 

27 

4171 

15. 

(( 

27  30 

4468 

• 

Shot 

10  Inch  Columbiad. 

18. 

128  lbs. 

0        • 

394 

Axis  of  gun  16  feet 

On  Mrbette  carriage 

i{ 

1 

752 

above  the  water. 

■ 

<t 

2 

1002 

t( 

3 

1230 

i 

ei 

4 

1570 

a 

5 

1814 

a 

6 

2037 

Shot  ceased  to  ric- 

11 

8 

2519 

ochet  on  water. 

(C 

10 

2777 

• 

(C 

15 

3525 

i( 

'20 

4020 

(( 

25 

4304 

u 

30 

4761 

(( 

35 

5433 

20. 

(( 

39  15 

5654 

• 

TABLES   OF   RANGES   AND   ELEVATIONS. 


71 


RANGES  OF  HEAVY  ORDNANCE— Con<m«c(f. 


Kind  of  Ordnance. 

Powder. 

Ball. 

1 

Eletation 

Range. 

Remabkb. 

Lbs. 

Shell 

o 

Yards. 

10  Inch  Columbiad— 

12. 

100  lbs. 

1 

800 

Continued. 

li 

2 

1012 

ii 

3 

1184 

(( 

4 

•1443 

(t 

5 

1604 

18. 

(( 

0 

448 

"* 

« 

1 

747 

(t 

2 

1100 

IS 

3 

1239 

<< 

4 

1611 

(( 

5 

1865 

♦ 

il 

6 

2209 

' 

li 

8 

2489 

• 

<i 

10 

2848 

i( 

15 

3200 

(( 

20. 

3885 

it 

25 

4150 

ii 

30 

4651 

. 

ii 

"35 

4828  jTime  flight,  35  sec. 

Shell 

1 

12  Inch  Columbiad. 

20. 

172  lbs. 

10 

2770 

Time  flight,  11  sec. 

(( 

15 

3731 

a          a      16      u 

ii 

22 

4280 

ii          a     20     ** 

ii 

25 

4718 

it          a     26      « 

• 

ii 

30 

5004 

ii 

35 

5339 

"        u    32    ii 

a 

37 

5266 

it           a     31      it 

ii 

39 

5064 

25. 

ii 

10 

2881 

it          a     11.5  u 

a 

15 

3542 

c«         it     15     it 

a 

30 

5102 

a 

35 

5409 

it        it    32    if 

a 

37 

5373 

a          it     32      if 

• 

ii 

39 

5506 

ii        ii    35     (I 

Shell 

35 

5644 

180  lbs. 

•    39 

5615 

28. 

(( 

35 

5671 

(( 

39 

5761 

3i  miles.     Time, 

36  seconds. 

Shell 

13  Inch  Sea-Coast 

20. 

200  lbs. 

45 

4325 

Mortar. 

72 


NOTES   ON  ARTILLERY. 


RANGES  OF  HEAVY  ORDIi ANCE— Continued. 


Kind  of  Ordnance. 

Powder. 

Ball. 

Elevation. 

Range. 

flEMAKES. 

Lbs. 

Shell 

o 

Yards. 

12  Inch  Sea-Coast 

20. 

20U  lbs. 

45 

4625 

Experimental. 

Mortar. 

Shell 

.,  _ 

10  Inch  Sea-Coast 

10. 

98  lbs. 

45 

4250 

Time,  flight  36  sec. 

Mortar. 

• 

Shell 

10  In.  SieCxE  Mortar. 

1. 

90  lbs. 

45 

300 

Time  flight,  6.5  s. 

1.5 

(( 

45 

700 

"        «    12  sec. 

2. 

(C 

45 

1000 

((          a     14    ti  . 

2.5 

<( 

45 

1300 

u        «    16   t( 

3. 

i( 

45 

1600 

«        "    18  " 

3.5 

t( 

45 

1900 

a          a     19    a 

4. 

,(( 

45 

2100 

a          a     21    « 

Lbs.  oz. 

Shell 

8  Inch  Siege  Mortar. 

0  10| 

46  lbs. 

45 

500' 

Time  flight,  10  sec. 

(From  Griffith's  Artil- 

13f 

(C 

45 

,    600 

a          ^^      \\     a 

lerist's  Manual.) 

1 

(C 

45 

750 

((                   (C           12i" 

1     2 

a 

45 

900 

(c          ii      13'    a 

1     3| 

(t 

45 

1000 

it          a      131  <f 

1     4| 

(C 

45 

1100 

a          a      14     a 

1     6 

(( 

45 

1200 

it          a      141  a 

Oz. 

Shell 

24  Pounder  Coehorn 

0.5    < 

17  lbs. 

45 

25 

Mortar. 

1. 

« 

45 

68 

1.5 

(C 

45 

104 

1.75 

ii 

45 

143 

2. 

a 

45 

165 

2.75 

(( 

45 

260 

' 

4. 

a 

45 

422 

6. 

e( 

45 

900 

8. 

tt 

45 

1200 

- 

TABLES   OF   RANGES  AND   ELEVATIONS. 


73 


PENETRATION  OF  SHOT  IN  MASONRY. 

FROM  EXPERIMENTS  MADE  AT  METZ  IN  1834,  AT  A  DISTANCE  OP  219  YARDS 


Calibre. 

Charge  in 

Penetration 

« 

weight  of  Shot. 

in  inches. 

36* 

i 

24 

24 

i 

22 

li 

i 

21 

C( 

i 

20 

i< 

i 

14 

12 

i 

16 

'  i( 

I 

14 

a 

i 

13 

(( 

* 

11 

PENETRATION  IN  OAK  WOOD, 

AT  A  DISTANCE  OF  219  YARDS. 


Calibre. 

Charge  in 

Penetration 

weight  of  ball. 

in  inches. 

36 

i 

58 

24 

i 

64 

(( 

i 

51 

u 

i 

48 

(( 

i 

42 

12 

i 

^8 

u 

k 

36 

(( 

i 

31 

(( 

i 

27 

*  The  36  pounder  corresponds  nearly  with  our  42  pounder. 


74 


NOTES   ON  ARTILLERY. 


PENETRATION  IN  OAK  WOOB, 

AT  A  DISTANCE  OF  219  YARDS. 


Calibre. 

Charge. 

Penetration 
in  inches.  .. 

Howitzer. 

Lbs. 

, 

8  inch. 

4.4 

22 

(( 

3.3 

18 

(C 

•      22 

12 

12  pdr. 

2.2 

22 

(C 

1.1 

13 

PENETRATION  IN  COMPACT  EARTH,  (HALF  SAND  AND  HALf  CLAY,) 

AT  A  DISTANCE  OF  219  YARDS. 


Calibre. 

Charge. 

Penetration 
in  inches. 

36 

i 

97 

24 

i 

91 

(( 

i 

77 

12 

i 

54 

11 

i 

52 

i( 

i 

44 

Howitzer. 

8  inch. 

4.4  lbs. 

41 

u 

2.2    " 

29 

24  pdr. 

2.2    " 

36 

u 

1.1    " 

27 

TABLES   OF   RANGES   AND   ELEVATIONS. 


75 


The  penetrations  in  other  kinds  of  earth  are  found  by  mul- 
tiplying their  numbers :    for  sand  mixed  with  gravel,  by  the 

co-efficient 0.63 

For  wet  potter's  clay,,  by  the  co-efficient  .         .  *      1.44 

For  light  earth  settled,  by        .         .         .         !    ■      .         1.50 

In  general,  sand,  sandy  earth  mixed  with  gravel  or  small 
stones,  chalk  and  turf,  resist  shot  better  than  the  productive 
earth  or  clay,  or  earth  that  retains  water. 

INITIAL  VELOCITIES  OF  CANNON  BALLS.    . 


Calibre. 

Projectiles. 

Charge. 

Initial  Velocity. 

Lbs. 

Feet. 

6  pounder, 

Shot 

1.25 

1439 

i{ 

li 

2. 

1741 

12  pounder, 

11 

2.'5 

1486 

i( 

11  , 

4. 

1826 

12  pdr.  howitzer, 

Shell 

1.25 

1178 

24  pounder, 

Shot 

4. 

1440 

li 

li 

6. 

1680 

cc 

a 

8. 

1870 

32  pounder, 

11 

5.33 

1430 

li 

11 

8. 

1640 

li 

Canister 

4. 

1172 

it 

1 

Grape 

4. 

1133 

76 


NOTES   ON  ARTILLERY. 


TERMINAL  VELOCITIES  OF  CANNON  BALLS. 

The  velocity*  of  a  projectile  diminishes  from  the  commence- 
ment of  its  flight  to  a  point  a  little  beyond  the  summit  of  the 
trajectory:  it  then  increases  to  a  certain  limit.  The  following 
table  gives  the  final  velocities : 


Shot. 

Shell. 

Calibre,     .     . 

42 

24 

18 

12 

6 

13  in. 

10  in. 

Sin. 

24pdr 

CO    at 

Final    velocity 
of  descent  in 
feet,    .     .     . 

485 

455 

425 

410 

360 

585 

505 

445 

375 

213 

luWidjing,  l^ookellmg  ^  Statiaiierg  ^staHisljnient 

14.5    MAIN    STREET. 


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